Transmitting/receiving system and broadcast signal processing method

ABSTRACT

A receiving system and a method for receiving and processing a broadcast signal including mobile service data are disclosed. The receiving system includes a tuner, a demodulator, a block decoder and an RS frame decoder. The tuner receives a broadcast signal including first mobile service data and second mobile service data. The demodulator demodulates the broadcast signal. The block decoder performs turbo-decoding on the first and second mobile service data included in the demodulated broadcast signal. The RS frame decoder builds a primary RS frame by collecting the turbo-decoded first mobile service data and performs error correction decoding on the primary RS frame. The RS frame decoder also builds a secondary RS frame by collecting the second mobile service data and performs error correction decoding on the secondary RS frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a digital broadcasting system fortransmitting and receiving a digital broadcast signal, and moreparticularly, to a transmitting system for processing and transmittingthe digital broadcast signal, and a receiving system for receiving andprocessing the digital broadcast signal and, a method of processing abroadcast signal in the transmitting system and the receiving system.

2. Discussion of the Related Art

The Vestigial Sideband (VSB) transmission mode, which is adopted as thestandard for digital broadcasting in North America and the Republic ofKorea, is a system using a single carrier method. Therefore, thereceiving performance of the digital broadcast receiving system may bedeteriorated in a poor channel environment. Particularly, sinceresistance to changes in channels and noise is more highly required whenusing portable and/or mobile broadcast receivers, the receivingperformance may be even more deteriorated when transmitting mobileservice data by the VSB transmission mode.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide atransmitting system and a receiving system and a method of processingbroadcast signal that are highly resistant to channel changes and noise.

Another object of the present invention is to provide a transmittingsystem and a receiving system and a method of processing broadcastsignal that can enhance the receiving performance of the receivingsystem by performing additional encoding on mobile service data and bytransmitting the processed data to the receiving system.

A further object of the present invention is to provide a transmittingsystem and a receiving system and a method of processing broadcastsignal that can also enhance the receiving performance of the receivingsystem by inserting known data already known in accordance with apre-agreement between the receiving system and the transmitting systemin a predetermined region within a data region.

Another object of the present invention is to provide a transmittingsystem, a receiving system, and a method of processing broadcast signalthat may increase a transmission rate of mobile service data by using atleast a portion of a channel capacity, to which data for main serviceshave been transmitted.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, areceiving system may includes a tuner, a demodulator, a block decoderand an RS frame decoder. The tuner receives a broadcast signal includingfirst mobile service data and second mobile service data through a slot.Herein, the slot is configured of M1 number of packets, among the M1number of packets included in the slot, M2 number of packets include thefirst mobile service data and a plurality of known data sequences, amongremaining M3 number of packets, at least one packet includes the secondmobile service data and M1=M2+M3, M2>M3. The demodulator demodulates thebroadcast signal. The block decoder performs turbo-decoding on the firstand second mobile service data included in the demodulated broadcastsignal. And the RS frame decoder builds a primary RS frame by collectingthe turbo-decoded first mobile service data and performs errorcorrection decoding on the primary RS frame. The RS frame decoder alsobuilds a secondary RS frame by collecting the second mobile service dataand performs error correction decoding on the secondary RS frame.

Among the M2 number packets included in the slot, at least one packetincludes both first mobile service data and second mobile service data.

Among the M3 number packets included in the slot, at least one packetincludes a long known data sequence. Furthermore, among the M3 numberpackets included in the slot, at least one packet includes second mobileservice data and a plurality of short known data sequences.

Among the M3 number packets included in the slot, at least one packetincludes main service data.

Furthermore, the receiving system may further include a channelequalizer. The channel equalizer performs channel equalization on thefirst mobile service data included in the demodulated broadcast signalbased on an indirect equalization method that estimates channel impulseresponses (CIRs) using the known data sequences and calculates anequalization coefficient by interpolating or extrapolating the estimatedCIRs. In addition, the channel equalizer performs channel equalizationon the second mobile service data included in the demodulated broadcastsignal based on a direct equalization method that extracts an error froma output of the channel equalizer and updates an equalizationcoefficient based on the extracted error. Moreover, the channelequalizer performs channel equalization on the first and second mobileservice data included in the demodulated broadcast signal based on anindirect equalization method that estimates CIRs using the known datasequences and calculates an equalization coefficient by interpolating orextrapolating the estimated CIRs.

A method for processing broadcast signals in a receiving system includesreceiving a broadcast signal including first mobile service data andsecond mobile service data through a slot, wherein the slot isconfigured of M1 number of packets, wherein, among the M1 number ofpackets included in the slot, M2 number of packets include the firstmobile service data and a plurality of known data sequences, wherein,among remaining M3 number of packets, at least one packet includes thesecond mobile service data and wherein M1=M2+M3, M2>M3, demodulating thebroadcast signal, performing turbo-decoding on the first and secondmobile service data included in the demodulated broadcast signal,building a primary RS frame by collecting the turbo-decoded first mobileservice data and performing error correction decoding on the primary RSframe, and building a secondary RS frame by collecting the second mobileservice data and performing error correction decoding on the secondaryRS frame.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a structure of a M/H frame for transmitting andreceiving mobile service data according to the present invention;

FIG. 2 illustrates an exemplary structure of a VSB frame;

FIG. 3 illustrates a distinguishing example of a region for a mobileservice and a region for a main service within one slot at a packetlevel according to the present invention;

FIG. 4 illustrates a mapping example of the positions to which the first4 slots of a sub-frame are assigned with respect to a VSB frame in aspace region;

FIG. 5 illustrates an alignment of data after being data interleaved andidentified;

FIG. 6 illustrates an enlarged portion of the data group shown in FIG. 5for a better understanding of the present invention;

FIG. 7 illustrates an alignment of data before being data interleavedand identified;

FIG. 8 illustrates an enlarged portion of the data group shown in FIG. 7for a better understanding of the present invention;

FIG. 9 illustrates an exemplary assignment order of data groups beingassigned to one of 5 sub-frames according to the present invention;

FIG. 10 illustrates an example of assigning a single parade to an M/Hframe according to the present invention;

FIG. 11 illustrates an example of assigning 3 parades to an M/H frameaccording to the present invention;

FIG. 12 illustrates an example of expanding the assignment process of 3parades to 5 sub-frames within an M/H frame;

FIG. 13 illustrates a data transmission structure according to anembodiment of the present invention, wherein signaling data are includedin a data group so as to be transmitted;

FIG. 14 illustrates a block diagram showing a general structure of atransmitting system according to an embodiment of the present invention;

FIG. 15 is a diagram illustrating an example of RS frame payloadaccording to the present invention;

FIG. 16 is a diagram illustrating a structure of an M/H header within anM/H service data packet according to the present invention;

FIG. 17( a) and FIG. 17( b) are diagrams illustrating another example ofRS frame payload according to the present invention;

FIG. 18 illustrates a block diagram showing an example of a servicemultiplexer of FIG. 14;

FIG. 19 illustrates a block diagram showing an embodiment of atransmitter of FIG. 14;

FIG. 20 illustrates a block diagram showing an example of apre-processor of FIG. 19;

FIG. 21 illustrates a conceptual block diagram of the M/H frame encoderof FIG. 20;

FIG. 22 illustrates a detailed block diagram of an RS frame encoder ofFIG. 21;

FIG. 23( a) and FIG. 23( b) illustrate a process of one or two RS framebeing divided into several portions, based upon an RS frame mode value,and a process of each portion being assigned to a corresponding regionwithin the respective data group;

FIG. 24( a) to FIG. 24( c) illustrate error correction encoding anderror detection encoding processes according to an embodiment of thepresent invention;

FIG. 25( a) to FIG. 25( d) illustrate an example of performing a rowpermutation (or interleaving) process in super frame units according tothe present invention;

FIG. 26( a) and FIG. 26( b) illustrate an example which a paradeconsists of two RS frames;

FIG. 27( a) and FIG. 27( b) illustrate an exemplary process of dividingan RS frame for configuring a data group according to the presentinvention;

FIG. 28 illustrates a block diagram of a block processor according to anembodiment of the present invention;

FIG. 29 illustrates a detailed block diagram of a convolution encoder ofthe block processor;

FIG. 30 illustrates a symbol interleaver of the block processor;

FIG. 31 illustrates a block diagram of a group formatter according to anembodiment of the present invention;

FIG. 32 illustrates a block diagram of a trellis encoder according to anembodiment of the present invention;

FIG. 33 illustrates an example of assigning signaling information areaaccording to an embodiment of the present invention;

FIG. 34 illustrates a detailed block diagram of a signaling encoderaccording to the present invention;

FIG. 35 illustrates an example of a syntax structure of TPC dataaccording to the present invention;

FIG. 36 illustrates an example of a transmission scenario of the TPCdata and the FIC data level according to the present invention;

FIG. 37 illustrates an example of power saving of in a receiver by aparade unit according to the present invention;

FIG. 38 illustrates an example of a training sequence in a data groupbefore trellis encoding according to the present invention;

FIG. 39 illustrates an example of a training sequence in a data groupafter trellis encoding according to the present invention;

FIG. 40 (a) illustrates an exemplary data group structure according tothe present invention, when mobile service data exist in consecutiveslots within a packet domain before being interleaved;

FIG. 40 (b) illustrates an exemplary data group structure according tothe present invention, when mobile service data exist in consecutiveslots within a segment domain after being interleaved;

FIG. 41 (a) illustrates an example of second mobile service data andmain service data being allocated to a bonding region within a packetdomain prior to being interleaved.

FIG. 41 (b) illustrates an enlarged view of the bonding region shown inFIG. 41 (a);

FIG. 42 illustrates an example of second mobile service data and mainservice data being allocated to a bonding area within a segment domainafter being interleaved;

FIG. 43 illustrates an example of known data bytes being uniformlyinserted in the bonding area within a segment domain after beinginterleaved;

FIG. 44 illustrates an example inserting only second mobile service datain the bonding area within a segment domain after being interleaved,without inserting main service data, and inserting short known datasequences in-between the second mobile service data, according to thepresent invention;

FIG. 45 illustrates an example inserting only second mobile service datain the bonding area within a segment domain after being interleaved,without inserting main service data, and inserting long known datasequences in-between the second mobile service data, according to thepresent invention.

FIG. 46( a) to FIG. 46( c) respectively illustrate different types ofbonding data groups according to the present invention;

FIG. 47 (a) to FIG. 47( c) respectively illustrate exemplary rules forallocating general data groups and bonding data groups to a singlesubframe;

FIG. 48 illustrates a block diagram of a receiving system according toan embodiment of the present invention;

FIG. 49 is a block diagram showing an example of a demodulating unit inthe receiving system;

FIG. 50 is a block diagram showing an example of an operation controllerof FIG. 49;

FIG. 51 illustrates an example of linear interpolation according to thepresent invention;

FIG. 52 illustrates an example of linear extrapolation according to thepresent invention;

FIG. 53 illustrates a block diagram of a channel equalizer according toan embodiment of the present invention;

FIG. 54 illustrates a block diagram of a channel equalizer according toanother embodiment of the present invention;

FIG. 55 illustrates a block diagram of a block decoder according to anembodiment of the present invention;

FIG. 56( a) and FIG. 56( b) illustrate an exemplary process ofconfiguring one or two RS frame by collecting a plurality of portionsaccording to the present invention; and

FIG. 57 and FIG. 58 illustrate process steps of error correctiondecoding according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. In addition,although the terms used in the present invention are selected fromgenerally known and used terms, some of the terms mentioned in thedescription of the present invention have been selected by the applicantat his or her discretion, the detailed meanings of which are describedin relevant parts of the description herein. Furthermore, it is requiredthat the present invention is understood, not simply by the actual termsused but by the meaning of each term lying within.

Among the terms used in the description of the present invention, mainservice data correspond to data that can be received by a fixedreceiving system and may include audio/video (A/V) data. Morespecifically, the main service data may include A/V data of highdefinition (HD) or standard definition (SD) levels and may also includediverse data types required for data broadcasting. Also, the known datacorrespond to data pre-known in accordance with a pre-arranged agreementbetween the receiving system and the transmitting system.

Additionally, among the terms used in the present invention, “M/H (orMH)” corresponds to the initials of “mobile” and “handheld” andrepresents the opposite concept of a fixed-type system. Furthermore, theM/H service data may include at least one of mobile service data andhandheld service data, and will also be referred to as “mobile servicedata” for simplicity. Herein, the mobile service data not onlycorrespond to M/H service data but may also include any type of servicedata with mobile or portable characteristics. Therefore, the mobileservice data according to the present invention are not limited only tothe M/H service data.

The above-described mobile service data may correspond to data havinginformation, such as program execution files, stock information, and soon, and may also correspond to A/V data. Most particularly, the mobileservice data may correspond to A/V data having lower resolution andlower data rate as compared to the main service data. For example, if anA/V codec that is used for a conventional main service corresponds to aMPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable videocoding (SVC) having better image compression efficiency may be used asthe A/V codec for the mobile service. Furthermore, any type of data maybe transmitted as the mobile service data. For example, transportprotocol expert group (TPEG) data for broadcasting real-timetransportation information may be transmitted as the main service data.

Also, a data service using the mobile service data may include weatherforecast services, traffic information services, stock informationservices, viewer participation quiz programs, real-time polls andsurveys, interactive education broadcast programs, gaming services,services providing information on synopsis, character, background music,and filming sites of soap operas or series, services providinginformation on past match scores and player profiles and achievements,and services providing information on product information and programsclassified by service, medium, time, and theme enabling purchase ordersto be processed. Herein, the present invention is not limited only tothe services mentioned above.

In the present invention, the transmitting system provides backwardcompatibility in the main service data so as to be received by theconventional receiving system. Herein, the main service data and themobile service data are multiplexed to the same physical channel andthen transmitted.

Furthermore, the transmitting system according to the present inventionperforms additional encoding on the mobile service data and inserts thedata already known by the receiving system and transmitting system(e.g., known data), thereby transmitting the processed data.

Furthermore, the present invention relates to enabling a larger amountof mobile service data to be transmitted. In order to do so, accordingto an exemplary embodiment of the present invention, the presentinvention may use a portion of the channel capacity, to which the datafor main services have been transmitted, so as to transmit data for themobile services. Or, the present invention may use the whole channelcapacity, to which the data for main services have been transmitted, soas to transmit data for the mobile services.

The data for mobile services correspond to data required for providingmobile services. Accordingly, the data for mobile services may includethe actual mobile service data as well as known data, signaling data, RSparity data for performing error correction on the mobile service data.In the description of the present invention, the data for mobileservices will also be referred to as mobile service data for simplicity.

Therefore, when using the transmitting system according to the presentinvention, the receiving system may receive the mobile service dataduring a mobile state and may also receive the mobile service data withstability despite various distortion and noise occurring within thechannel.

M/H Frame Structure

In the embodiment of the present invention, the mobile service data arefirst multiplexed with main service data in M/H frame units and, then,modulated in a VSB mode and transmitted to the receiving system.

At this point, one M/H frame consists of K1 number of sub-frames,wherein one sub-frame includes K2 number of slots. Also, each slot maybe configured of K3 number of data packets. In the embodiment of thepresent invention, K1 will be set to 5, K2 will be set to 16, and K3will be set to 156 (i.e., K1=5, K2=16, and K3=156). The values for K1,K2, and K3 presented in this embodiment either correspond to valuesaccording to a preferred embodiment or are merely exemplary. Therefore,the above-mentioned values will not limit the scope of the presentinvention.

FIG. 1 illustrates a structure of an M/H frame for transmitting andreceiving mobile service data according to the present invention. In theexample shown in FIG. 1, one M/H frame consists of 5 sub-frames, whereineach sub-frame includes 16 slots. In this case, the M/H frame accordingto the present invention includes 5 sub-frames and 80 slots. Also, in apacket level, one slot is configured of 156 data packets (i.e.,transport stream packets), and in a symbol level, one slot is configuredof 156 data segments. Herein, the size of one slot corresponds to onehalf (½) of a VSB field. More specifically, since one 207-byte datapacket has the same amount of data as a data segment, a data packetprior to being interleaved may also be used as a data segment.

At this point, two VSB fields are grouped to form a VSB frame.

FIG. 2 illustrates an exemplary structure of a VSB frame, wherein oneVSB frame consists of 2 VSB fields (i.e., an odd field and an evenfield). Herein, each VSB field includes a field synchronization segmentand 312 data segments.

FIG. 3 illustrates the structure of a slot within a packet domain. Inthis case, one slot may consist of M1 number of packets (e.g., 156packets).

The above-mentioned slot corresponds to a basic time cycle formultiplexing mobile service data and main service data. Herein, when aslot is defined in packet units, one slot corresponds to a time periodof 156 packets. Such slot may include mobile service data, or such slotmay consist only of main service data.

When a data group including mobile service data is transmitting duringone slot, one data group is transmitted through the first M2 number ofpackets (e.g., 118 packets) within the slot, and main service data aretransmitted through the remaining M3 number of packets (e.g., 38packets). More specifically, main service data of at least 4.72 Mbps aretransmitted through 38 packets within one slot. In other words,approximately 24.4% (=38/(118+38)*100) of main service data aretransmitted through 38 packets within one slot. As another example, if adata group does not exist in a slot, the corresponding slots maytransmit 156 packets of main service data.

Meanwhile, when the slots are assigned to a VSB frame, an offset existsfor each assigned position.

FIG. 4 illustrates a mapping example of the positions to which the first4 slots of a sub-frame are assigned with respect to a VSB frame in aspace region.

Referring to FIG. 4, a 38^(th) data packet (TS packet #37) of a 1^(st)slot (Slot #0) is mapped to the 1^(st) data packet of an odd VSB field.A 38^(th) data packet (TS packet #37) of a 2^(nd) Slot (Slot #1) ismapped to the 157^(th) data packet of an odd VSB field. Also, a 38^(th)data packet (TS packet #37) of a 3^(rd) Slot (Slot #2) is mapped to the1^(st) data packet of an even VSB field. And, a 38^(th) data packet (TSpacket #37) of a 4^(th) slot (Slot #3) is mapped to the 157^(th) datapacket of an even VSB field. Similarly, the remaining 12 slots withinthe corresponding sub-frame are mapped in the subsequent VSB framesusing the same method.

Meanwhile, one data group may be divided into at least one or morehierarchical regions. And, depending upon the characteristics of eachhierarchical region, the type of mobile service data being inserted ineach region may vary. For example, the data group within each region maybe divided (or categorized) based upon the receiving performance.

In an example given in the present invention, a data group is dividedinto regions A, B, C, and D in a data configuration after datainterleaving.

FIG. 5 illustrates an alignment of data after being data interleaved andidentified. FIG. 6 illustrates an enlarged portion of the data groupshown in FIG. 5 for a better understanding of the present invention.FIG. 7 illustrates an alignment of data before being data interleavedand identified. And, FIG. 8 illustrates an enlarged portion of the datagroup shown in FIG. 7 for a better understanding of the presentinvention. More specifically, a data structure identical to that shownin FIG. 5 is transmitted to a receiving system. In other words, one datapacket is data-interleaved so as to be scattered to a plurality of datasegments, thereby being transmitted to the receiving system. FIG. 5illustrates an example of one data group being scattered to 170 datasegments. At this point, since one 207-byte packet has the same amountof data as one data segment, the packet that is not yet processed withdata-interleaving may be used as the data segment.

FIG. 5 shows an example of dividing a data group prior to beingdata-interleaved into 10 M/H blocks (i.e., M/H block 1 (B1) to M/H block10 (B10)). In this example, each M/H block has the length of 16segments. Referring to FIG. 5, only the RS parity data are allocated toa portion of 5 segments before the M/H block 1 (B1) and 5 segmentsbehind the M/H block 10 (B10). The RS parity data are excluded inregions A to D of the data group.

More specifically, when it is assumed that one data group is dividedinto regions A, B, C, and D, each M/H block may be included in any oneof region A to region D depending upon the characteristic of each M/Hblock within the data group. At this point, according to an embodimentof the present invention, each M/H block may be included in any one ofregion A to region D based upon an interference level of main servicedata.

Herein, the data group is divided into a plurality of regions to be usedfor different purposes. More specifically, a region of the main servicedata having no interference or a very low interference level may beconsidered to have a more resistant (or stronger) receiving performanceas compared to regions having higher interference levels. Additionally,when using a system inserting and transmitting known data in the datagroup, wherein the known data are known based upon an agreement betweenthe transmitting system and the receiving system, and when consecutivelylong known data are to be periodically inserted in the mobile servicedata, the known data having a predetermined length may be periodicallyinserted in the region having no interference from the main service data(i.e., a region wherein the main service data are not mixed). However,due to interference from the main service data, it is difficult toperiodically insert known data and also to insert consecutively longknown data to a region having interference from the main service data.

Referring to FIG. 5, M/H block 4 (B4) to M/H block 7 (B7) correspond toregions without interference of the main service data. M/H block 4 (B4)to M/H block 7 (B7) within the data group shown in FIG. 5 correspond toa region where no interference from the main service data occurs. Inthis example, a long known data sequence is inserted at both thebeginning and end of each M/H block. In the description of the presentinvention, the region including M/H block 4 (B4) to M/H block 7 (B7)will be referred to as “region A (=B4+B5+B6+B7)”. As described above,when the data group includes region A having a long known data sequenceinserted at both the beginning and end of each M/H block, the receivingsystem is capable of performing equalization by using the channelinformation that can be obtained from the known data. Therefore, thestrongest equalizing performance may be yielded (or obtained) from oneof region A to region D.

In the example of the data group shown in FIG. 5, M/H block 3 (B3) andM/H block 8 (B8) correspond to a region having little interference fromthe main service data. Herein, a long known data sequence is inserted inonly one side of each M/H block B3 and B8. More specifically, due to theinterference from the main service data, a long known data sequence isinserted at the end of M/H block 3 (B3), and another long known datasequence is inserted at the beginning of M/H block 8 (B8). In thepresent invention, the region including M/H block 3 (B3) and M/H block 8(B8) will be referred to as “region B(=B3+B8)”. As described above, whenthe data group includes region B having a long known data sequenceinserted at only one side (beginning or end) of each M/H block, thereceiving system is capable of performing equalization by using thechannel information that can be obtained from the known data. Therefore,a stronger equalizing performance as compared to region C/D may beyielded (or obtained).

Referring to FIG. 5, M/H block 2 (B2) and M/H block 9 (B9) correspond toa region having more interference from the main service data as comparedto region B. A long known data sequence cannot be inserted in any sideof M/H block 2 (B2) and M/H block 9 (B9). Herein, the region includingM/H block (B2) and M/H block 9 (B9) will be referred to as “regionC(=B2+B9)”. Finally, in the example shown in FIG. 5, M/H block 1 (B1)and M/H block 10 (B10) correspond to a region having more interferencefrom the main service data as compared to region C. Similarly, a longknown data sequence cannot be inserted in any side of M/H block 1 (B1)and M/H block 10 (B10).

Herein, the region including M/H block 1 (B1) and M/H block 10 (B10)will be referred to as “region D (=B1+B10)”. Since region C/D is spacedfurther apart from the known data sequence, when the channel environmentundergoes frequent and abrupt changes, the receiving performance ofregion C/D may be deteriorated.

FIG. 7 illustrates a data structure prior to data interleaving. Morespecifically, FIG. 7 illustrates an example of 118 data packets beingallocated to a data group. FIG. 7 shows an example of a data groupconsisting of 118 data packets, wherein, based upon a reference packet(e.g., a 1^(st) packet (or data segment) or 157^(th) packet (or datasegment) after a field synchronization signal), when allocating datapackets to a VSB frame, 37 packets are included before the referencepacket and 81 packets (including the reference packet) are includedafterwards.

In other words, with reference to FIG. 5, a field synchronization signalis placed (or assigned) between M/H block 2 (B2) and M/H block 3 (B3).Accordingly, this indicates that the slot has an off-set of 37 datapackets with respect to the corresponding VSB field.

The size of the data groups, number of hierarchical regions within thedata group, the size of each region, the number of M/H blocks includedin each region, the size of each M/H block, and so on described aboveare merely exemplary. Therefore, the present invention will not belimited to the examples described above.

FIG. 9 illustrates an exemplary assignment order of data groups beingassigned to one of 5 sub-frames, wherein the 5 sub-frames configure anM/H frame. For example, the method of assigning data groups may beidentically applied to all M/H frames or differently applied to each M/Hframe. Furthermore, the method of assigning data groups may beidentically applied to all sub-frames or differently applied to eachsub-frame. At this point, when it is assumed that the data groups areassigned using the same method in all sub-frames of the correspondingM/H frame, the total number of data groups being assigned to an M/Hframe is equal to a multiple of ‘5’.

According to the embodiment of the present invention, a plurality ofconsecutive data groups is assigned to be spaced as far apart from oneanother as possible within the M/H frame. Thus, the system can becapable of responding promptly and effectively to any burst error thatmay occur within a sub-frame.

For example, when it is assumed that 3 data groups are assigned to asub-frame, the data groups are assigned to a 1^(st) slot (Slot #0), a5^(th) slot (Slot #4), and a 9^(th) slot (Slot #8) in the sub-frame,respectively. FIG. 9 illustrates an example of assigning 16 data groupsin one sub-frame using the above-described pattern (or rule). In otherwords, each data group is serially assigned to 16 slots corresponding tothe following numbers: 0, 8, 4, 12, 1, 9, 5, 13, 2, 10, 6, 14, 3, 11, 7,and 15. Equation 1 below shows the above-described rule (or pattern) forassigning data groups in a sub-frame.

j=(4i+0)mod 16  Equation 1

Herein,

-   -   0=0 if i<4,    -   0=2 else if i<8,    -   0=1 else if i<12,    -   0=3 else.

Herein, j indicates the slot number within a sub-frame. The value of jmay range from 0 to 15 (i.e., 0≦j≦15). Also, value of i indicates thedata group number. The value of i may range from 0 to 15 (i.e., 0≦i≦15).

In the present invention, a collection of data groups included in an M/Hframe will be referred to as a “parade”. Based upon the RS frame mode,the parade transmits data of at least one specific RS frame.

The mobile service data within one RS frame may be assigned either toall of regions A/B/C/D within the corresponding data group, or to atleast one of regions A/B/C/D. In the embodiment of the presentinvention, the mobile service data within one RS frame may be assignedeither to all of regions A/B/C/D, or to at least one of regions A/B andregions C/D. If the mobile service data are assigned to the latter case(i.e., one of regions A/B and regions C/D), the RS frame being assignedto regions A/B and the RS frame being assigned to regions C/D within thecorresponding data group are different from one another.

In the description of the present invention, the RS frame being assignedto regions A/B within the corresponding data group will be referred toas a “primary RS frame”, and the RS frame being assigned to regions C/Dwithin the corresponding data group will be referred to as a “secondaryRS frame”, for simplicity. Also, the primary RS frame and the secondaryRS frame form (or configure) one parade. More specifically, when themobile service data within one RS frame are assigned either to all ofregions A/B/C/D within the corresponding data group, one paradetransmits one RS frame. In this case, also the RS frame will be referredto as a “primary RS frame”. Conversely, when the mobile service datawithin one RS frame are assigned either to at least one of regions A/Band regions C/D, one parade may transmit up to 2 RS frames.

More specifically, the RS frame mode indicates whether a paradetransmits one RS frame, or whether the parade transmits two RS frames.Table 1 below shows an example of the RS frame mode.

TABLE 1 RS frame mode (2 bits) Description 00 There is only one primaryRS frame for all group regions 01 There are two separate RS frames.Primary RS frame for group regions A and B Secondary RS frame for groupregions C and D 10 Reserved 11 Reserved

Table 1 illustrates an example of allocating 2 bits in order to indicatethe RS frame mode. For example, referring to Table 1, when the RS framemode value is equal to ‘00’, this indicates that one parade transmitsone RS frame. And, when the RS frame mode value is equal to ‘01’, thisindicates that one parade transmits two RS frames, i.e., the primary RSframe and the secondary RS frame. More specifically, when the RS framemode value is equal to ‘01’, data of the primary RS frame for regionsA/B are assigned and transmitted to regions A/B of the correspondingdata group. Similarly, data of the secondary RS frame for regions C/Dare assigned and transmitted to regions C/D of the corresponding datagroup.

As described in the assignment of data groups, the parades are alsoassigned to be spaced as far apart from one another as possible withinthe sub-frame. Thus, the system can be capable of responding promptlyand effectively to any burst error that may occur within a sub-frame.

Furthermore, the method of assigning parades may be identically appliedto all sub-frames or differently applied to each sub-frame. According tothe embodiment of the present invention, the parades may be assigneddifferently for each M/H frame and identically for all sub-frames withinan M/H frame. More specifically, the M/H frame structure may vary by M/Hframe units. Thus, an ensemble rate may be adjusted on a more frequentand flexible basis.

FIG. 10 illustrates an example of multiple data groups of a singleparade being assigned (or allocated) to an M/H frame. More specifically,FIG. 10 illustrates an example of a plurality of data groups included ina single parade, wherein the number of data groups included in asub-frame is equal to ‘3’, being allocated to an M/H frame. Referring toFIG. 10, 3 data groups are sequentially assigned to a sub-frame at acycle period of 4 slots. Accordingly, when this process is equallyperformed in the 5 sub-frames included in the corresponding M/H frame,15 data groups are assigned to a single M/H frame. Herein, the 15 datagroups correspond to data groups included in a parade. Therefore, sinceone sub-frame is configured of 4 VSB frame, and since 3 data groups areincluded in a sub-frame, the data group of the corresponding parade isnot assigned to one of the 4 VSB frames within a sub-frame.

For example, when it is assumed that one parade transmits one RS frame,and that a RS frame encoder located in a later block performsRS-encoding on the corresponding RS frame payload, thereby adding 24bytes of parity data to the corresponding RS frame payload andtransmitting the processed RS frame, the parity data occupyapproximately 11.37% (=24/(187+24)×100) of the total code word length.Meanwhile, when one sub-frame includes 3 data groups, and when the datagroups included in the parade are assigned, as shown in FIG. 10, a totalof 15 data groups form an RS frame. Accordingly, even when an erroroccurs in an entire data group due to a burst noise within a channel,the percentile is merely 6.67% (=1/15×100). Therefore, the receivingsystem may correct all errors by performing an erasure RS decodingprocess. More specifically, when the erasure RS decoding is performed, anumber of channel errors corresponding to the number of RS parity bytesmay be corrected. By doing so, the receiving system may correct theerror of at least one data group within one parade. Thus, the minimumburst noise length correctable by a RS frame is over 1 VSB frame.

Meanwhile, when data groups of a parade are assigned as described above,either main service data may be assigned between each data group, ordata groups corresponding to different parades may be assigned betweeneach data group. More specifically, data groups corresponding tomultiple parades may be assigned to one M/H frame.

Basically, the method of assigning data groups corresponding to multipleparades is very similar to the method of assigning data groupscorresponding to a single parade. In other words, data groups includedin other parades that are to be assigned to an M/H frame are alsorespectively assigned according to a cycle period of 4 slots.

At this point, data groups of a different parade may be sequentiallyassigned to the respective slots in a circular method. Herein, the datagroups are assigned to slots starting from the ones to which data groupsof the previous parade have not yet been assigned.

For example, when it is assumed that data groups corresponding to aparade are assigned as shown in FIG. 10, data groups corresponding tothe next parade may be assigned to a sub-frame starting either from the12^(th) slot of a sub-frame. However, this is merely exemplary. Inanother example, the data groups of the next parade may also besequentially assigned to a different slot within a sub-frame at a cycleperiod of 4 slots starting from the 3^(rd) slot.

FIG. 11 illustrates an example of transmitting 3 parades (Parade #0,Parade #1, and Parade #2) to an M/H frame. More specifically, FIG. 11illustrates an example of transmitting parades included in one of 5sub-frames, wherein the 5 sub-frames configure one M/H frame.

When the 1^(st) parade (Parade #0) includes 3 data groups for eachsub-frame, the positions of each data groups within the sub-frames maybe obtained by substituting values ‘0’ to ‘2’ for i in Equation 1. Morespecifically, the data groups of the 1^(st) parade (Parade #0) aresequentially assigned to the 1^(st), 5^(th), and 9^(th) slots (Slot #0,Slot #4, and Slot #8) within the sub-frame. Also, when the 2^(nd) paradeincludes 2 data groups for each sub-frame, the positions of each datagroups within the sub-frames may be obtained by substituting values ‘3’and ‘4’ for i in Equation 1.

More specifically, the data groups of the 2^(nd) parade (Parade #1) aresequentially assigned to the 2^(nd) and 12^(th) slots (Slot #3 and Slot#11) within the sub-frame.

Finally, when the 3^(rd) parade includes 2 data groups for eachsub-frame, the positions of each data groups within the sub-frames maybe obtained by substituting values ‘5’ and ‘6’ for i in Equation 1. Morespecifically, the data groups of the 3^(rd) parade (Parade #2) aresequentially assigned to the 7^(th) and 11^(th) slots (Slot #6 and Slot#10) within the sub-frame.

As described above, data groups of multiple parades may be assigned to asingle M/H frame, and, in each sub-frame, the data groups are seriallyallocated to a group space having 4 slots from left to right. Therefore,a number of groups of one parade per sub-frame (NOG) may correspond toany one integer from ‘1’ to ‘8’. Herein, since one M/H frame includes 5sub-frames, the total number of data groups within a parade that can beallocated to an M/H frame may correspond to any one multiple of ‘5’ranging from ‘5’ to ‘40’.

FIG. 12 illustrates an example of expanding the assignment process of 3parades, shown in FIG. 11, to 5 sub-frames within an M/H frame.

FIG. 13 illustrates a data transmission structure according to anembodiment of the present invention, wherein signaling data are includedin a data group so as to be transmitted.

As described above, an M/H frame is divided into 5 sub-frames. Datagroups corresponding to a plurality of parades co-exist in eachsub-frame. Herein, the data groups corresponding to each parade aregrouped by M/H frame units, thereby configuring a single parade.

Three parades (Parade #0, Parade #1, Parade #2) also exist in one M/Hframe of FIG. 13. At this time, a part (e.g., 37 bytes/data group) ofeach data group is used to forward fast information channel (FIC)information of mobile service data, which is encoded separately from RScode. An FIC region within a signaling information area assigned to eachdata group constitutes one FIC segment.

Meanwhile, in this embodiment, a collection of services is defined byconcept of M/H ensemble. One M/H ensemble has the same QoS, and is codedwith the same FEC code. Also, one M/H ensemble has unique identifier(i.e., ensemble_id), and is a collection of consecutive RS frames.

As shown in FIG. 13, FIC segment corresponding to each data groupdescribes service information of M/H ensemble to which correspondingdata group belongs.

General Description of the Transmitting System

FIG. 14 illustrates a block diagram showing a general structure of adigital broadcast transmitting system according to an embodiment of thepresent invention.

Herein, the digital broadcast transmitting includes a servicemultiplexer 100 and a transmitter 200. Herein, the service multiplexer100 is located in the studio of each broadcast station, and thetransmitter 200 is located in a site placed at a predetermined distancefrom the studio. The transmitter 200 may be located in a plurality ofdifferent locations. Also, for example, the plurality of transmittersmay share the same frequency. And, in this case, the plurality oftransmitters receives the same signal. This corresponds to datatransmission using Single Frequency Network (SFN). Accordingly, in thereceiving system, a channel equalizer may compensate signal distortion,which is caused by a reflected wave, so as to recover the originalsignal. In another example, the plurality of transmitters may havedifferent frequencies with respect to the same channel. This correspondsto data transmission using Multi Frequency Network (MFN).

A variety of methods may be used for data communication each of thetransmitters, which are located in remote positions, and the servicemultiplexer. For example, an interface standard such as a synchronousserial interface for transport of MPEG-2 data (SMPTE-310M). In theSMPTE-310M interface standard, a constant data rate is decided as anoutput data rate of the service multiplexer. For example, in case of the8VSB mode, the output data rate is 19.39 Mbps, and, in case of the 16VSBmode, the output data rate is 38.78 Mbps. Furthermore, in theconventional 8VSB mode transmitting system, a transport stream (TS)packet having a data rate of approximately 19.39 Mbps may be transmittedthrough a single physical channel. Also, in the transmitting systemaccording to the present invention provided with backward compatibilitywith the conventional transmitting system, additional encoding isperformed on the mobile service data. Thereafter, the additionallyencoded mobile service data are multiplexed with the main service datato a TS packet form, which is then transmitted. At this point, the datarate of the multiplexed TS packet is approximately 19.39 Mbps.

At this point, the service multiplexer 100 receives at least one type ofmain service data and table information (e.g., PSI/PSIP table data) foreach main service and encapsulates the received data into a transportstream (TS) packet.

Also, according to an embodiment of the present invention, the servicemultiplexer 100 receives at least one type of mobile service data andtable information (e.g., PSI/PSIP table data) for each mobile serviceand encapsulates the received data into a transport stream (TS) packet.

According to another embodiment of the present invention, the servicemultiplexer 100 receives a RS frame payload (or RS frame), which isconfigured of at least one type of mobile service data and tableinformation for each mobile service, and encapsulates the received RSframe payload data into mobile service data packets of a transportstream (TS) packet format.

And, the service multiplexer 100 multiplexes the encapsulated TS packetsfor main service and the encapsulated TS packets for mobile servicebased upon a predetermined multiplexing rule, thereby outputting themultiplexed TS packets to the transmitter 200.

At this point, the RS frame payload (or RS frame) has the size of N(row)×187 (column), as shown in FIG. 15. Herein, N represents the lengthof a row (i.e., number of columns), and 187 corresponds to the length ofa column (i.e., number of rows.

In the present invention, for convenience of description, each row ofthe N bytes will be referred to as M/H service data packet (or M/H TPpacket). The M/H service data packet includes M/H header of 2 bytes, astuffing region of k bytes, and M/H payload of N−2−k bytes. At thistime, k has a value of 0 or a value greater than 0. In this case, theM/H header of 2 bytes is only one example, and corresponding bytes canbe varied depending on a designer. Accordingly, the present inventionwill not be limited to such example.

The RS frame is created (or generated) by collecting table informationand/or IP datagrams having the size of N+2(row)×187+P(column) bytes.Also, an RS frame may include table information and IP datagramscorresponding to at least one or more mobile services. For example, IPdatagrams and table information of two different types of mobileservices, such as News (e.g., IP datagram for mobile service 1) andStocks (e.g., IP datagram for mobile service 2), may be included to asingle RS frame.

More specifically, table information of a section structure may beallocated, or IP datagrams of the mobile service data may be allocatedto an M/H payload within each M/H service data packet configuring the RSframe.

Alternatively, IP datagrams of the table information may be allocated,or IP datagrams of mobile service data may be allocated to an M/Hpayload within each M/H service data packet configuring the RS frame.

At this time, as the M/H service data packet includes M/H header, theM/H header may not reach N bytes.

In this case, stuffing bytes can be assigned to the remaining payloadpart of the corresponding M/H service data packet. For example, afterprogram table information is assigned to one M/H service data packet, ifthe length of the M/H service data packet is N−20 bytes including theM/H header, the stuffing bytes can be assigned to the remaining 20bytes.

FIG. 16 is a diagram illustrating examples of fields allocated to theM/H header region within the M/H service data packet according to thepresent invention. Examples of the fields include type_indicator field,error_indicator field, stuff_indicator field, and pointer field.

The type_indicator field can allocate 3 bits, for example, andrepresents a type of data allocated to payload within the correspondingM/H service data packet. In other words, the type_indicator fieldindicates whether data of the payload is IP datagram or program tableinformation. At this time, each data type constitutes one logicalchannel. In the logical channel which transmits the IP datagram, severalmobile services are multiplexed and then transmitted. Each mobileservice undergoes demultiplexing in the IP layer.

The error_indicator field can allocate 1 bit, for example, andrepresents whether the corresponding M/H service data packet has anerror. For example, if the error_indicator field has a value of 0, itmeans that there is no error in the corresponding M/H service datapacket. If the error_indicator field has a value of 1, it means thatthere may be an error in the corresponding M/H service data packet.

The stuff_indicator field can allocate 1 bit, for example, andrepresents whether stuffing byte exists in payload of the correspondingM/H service data packet. For example, if the stuff_indicator field has avalue of 0, it means that there is no stuffing byte in the correspondingM/H service data packet. If the stuff_indicator field has a value of 1,it means that stuffing byte exists in the corresponding M/H service datapacket.

The pointer field can allocate 11 bits, for example, and representsposition information where new data (i.e., new signaling information ornew IP datagram) starts in the corresponding M/H service data packet.

For example, if IP datagram for mobile service 1 and IP datagram formobile service 2 are allocated to the first M/H service data packetwithin the RS frame as illustrated in FIG. 15, the pointer field valuerepresents the start position of the IP datagram for mobile service 2within the M/H service data packet.

Also, if there is no new data in the corresponding M/H service datapacket, the corresponding field value is expressed as a maximum valueexemplarily. According to the embodiment of the present invention, since11 bits are allocated to the pointer field, if 2047 is expressed as thepointer field value, it means that there is no new data in the packet.The point where the pointer field value is 0 can be varied depending onthe type_indicator field value and the stuff_indicator field value.

It is to be understood that the order, the position, and the meaning ofthe fields allocated to the header within the M/H service data packetillustrated in FIG. 16 are exemplarily illustrated for understanding ofthe present invention. Since the order, the position and the meaning ofthe fields allocated to the header within the M/H service data packetand the number of additionally allocated fields can easily be modifiedby those skilled in the art, the present invention will not be limitedto the above example.

FIG. 17( a) and FIG. 17( b) illustrate another examples of RS framepayload according to the present invention. FIG. 17( a) illustrates anexample of primary RS frame payload to be allocated to regions A/Bwithin the data group, and FIG. 17( b) illustrates an example ofsecondary RS frame payload to be allocated to regions C/D within thedata group.

In FIG. 17( a) and FIG. 17( b), a column length (i.e., the number ofrows) of the RS frame payload to be allocated to the regions A/B and acolumn length (i.e., the number of rows) of the RS frame payload to beallocated to the regions C/D are 187 equally. However, row lengths (i.e,the number of columns) may be different from each other.

According to the embodiment of the present invention, when the rowlength of the primary RS frame payload to be allocated to the regionsA/B within the data group is N1 bytes and the row length of thesecondary RS frame payload to be allocated to the regions C/D within thedata group is N2 bytes, a condition of N1>N2 is satisfied. In this case,N1 and N2 can be varied depending on the transmission parameter or aregion of the data group, to which the corresponding RS frame payloadwill be transmitted.

For convenience of the description, each row of the N1 and N2 bytes willbe referred to as the M/H service data packet. The M/H service datapacket within the RS frame payload to be allocated to the regions A/Bwithin the data group can be comprised of M/H header of 2 bytes, astuffing region of k bytes, and M/H payload of N1−2−k bytes. At thistime, k has a value of 0 or a value greater than 0. Also, the M/Hservice data packet within the RS frame payload to be allocated to theregions C/D within the data group can be comprised of M/H header of 2bytes, a stuffing region of k bytes, and M/H payload of N2−2−k bytes. Atthis time, k has a value of 0 or a value greater than 0.

In the present invention, the primary RS frame payload for the regionsA/B within the data group and the secondary RS frame payload for theregions C/D within the data group can include at least one of IPdatagrams of signaling table information and mobile service data. Also,one RS frame payload can include IP datagram corresponding to one ormore mobile services.

Corresponding parts of FIG. 15 can be applied to the other parts, whichare not described in FIG. 17( a) and FIG. 17( b).

Meanwhile, the value of N, which corresponds to the number of columnswithin an RS frame payload, can be decided according to Equation 2.

$\begin{matrix}{N = {\lfloor \frac{5 \times {NoG} \times {PL}}{187 + P} \rfloor - 2}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Herein, NoG indicates the number of data groups assigned to a sub-frame.PL represents the number of SCCC payload data bytes assigned to a datagroup. And, P signifies the number of RS parity data bytes added to eachcolumn of the RS frame payload. Finally, └X┘ is the greatest integerthat is equal to or smaller than X.

More specifically, in Equation 2, PL corresponds to the length of an RSframe portion. The value of PL is equivalent to the number of SCCCpayload data bytes that are assigned to the corresponding data group.Herein, the value of PL may vary depending upon the RS frame mode, SCCCblock mode, and SCCC outer code mode. Table 2 to Table 5 belowrespectively show examples of PL values, which vary in accordance withthe RS frame mode, SCCC block mode, and SCCC outer code mode. The SCCCblock mode and the SCCC outer code mode will be described in detail in alater process.

TABLE 2 SCCC outer code mode for for for for Region Region Region RegionA B C D PL 00 00 00 00 9624 00 00 00 01 9372 00 00 01 00 8886 00 00 0101 8634 00 01 00 00 8403 00 01 00 01 8151 00 01 01 00 7665 00 01 01 017413 01 00 00 00 7023 01 00 00 01 6771 01 00 01 00 6285 01 00 01 01 603301 01 00 00 5802 01 01 00 01 5550 01 01 01 00 5064 01 01 01 01 4812Others Reserved

Table 2 shows an example of the PL values for each data group within anRS frame, wherein each PL value varies depending upon the SCCC outercode mode, when the RS frame mode value is equal to ‘00’, and when theSCCC block mode value is equal to ‘00’. For example, when it is assumedthat each SCCC outer code mode value of regions A/B/C/D within the datagroup is equal to ‘00’ (i.e., the block processor 302 of a later blockperforms encoding at a coding rate of ½), the PL value within each datagroup of the corresponding RS frame may be equal to 9624 bytes. Morespecifically, 9624 bytes of mobile service data within one RS frame maybe assigned to regions A/B/C/D of the corresponding data group.

TABLE 3 SCCC outer code mode PL 00 9624 01 4812 Others Reserved

Table 3 shows an example of the PL values for each data group within anRS frame, wherein each PL value varies depending upon the SCCC outercode mode, when the RS frame mode value is equal to ‘00’, and when theSCCC block mode value is equal to ‘01’.

TABLE 4 SCCC outer code mode For Region A for Region B PL 00 00 7644 0001 6423 01 00 5043 01 01 3822 Others Reserved

Table 4 shows an example of the PL values for each data group within aprimary RS frame, wherein each PL value varies depending upon the SCCCouter code mode, when the RS frame mode value is equal to ‘01’, and whenthe SCCC block mode value is equal to ‘00’. For example, when each SCCCouter code mode value of regions A/B is equal to ‘00’, 7644 bytes ofmobile service data within a primary RS frame may be assigned to regionsA/B of the corresponding data group.

TABLE 5 SCCC outer code mode For Region C for Region D PL 00 00 1980 0001 1728 01 00 1242 01 01  990 Others Reserved

Table 5 shows an example of the PL values for each data group within asecondary RS frame, wherein each PL value varies depending upon the SCCCouter code mode, when the RS frame mode value is equal to ‘01’, and whenthe SCCC block mode value is equal to ‘00’. For example, when each SCCCouter code mode value of regions C/D is equal to ‘00’, 1980 bytes ofmobile service data within a secondary RS frame may be assigned toregions C/D of the corresponding data group.

Service Multiplexer

FIG. 18 illustrates a block diagram showing an example of the servicemultiplexer. The service multiplexer includes a controller 110 forcontrolling the overall operations of the service multiplexer, a tableinformation generator 120 for the main service, a null packet generator130, an OM packet encapsulator 140, a mobile service multiplexer 150,and a transport multiplexer 160.

The transport multiplexer 160 may include a main service multiplexer 161and a transport stream (TS) packet multiplexer 162.

Referring to FIG. 18, at least one type of compression-encoded mainservice data and table data generated from the table informationgenerator 120 for the main services are inputted to the main servicemultiplexer 161 of the transport multiplexer 160. According to theembodiment of the present invention, the table information generator 120generates PSI/PSIP table data, which is configured in the form of anMPEG-2 private section.

The main service multiplexer 161 respectively encapsulates each of themain service data and the PSI/PSIP table data, which are being inputted,to MPEG-2 TS packet formats, thereby multiplexing the encapsulated TSpackets and outputting the multiplexed packets to the TS packetmultiplexer 162. Herein, the data packet being outputted from the mainservice multiplexer 161 will hereinafter be referred to as a mainservice data packet for simplicity.

The mobile service multiplexer 150 receives and respectivelyencapsulates at least one type of compression-encoded mobile servicedata and the table information (e.g., PSI/PSIP table data) for mobileservices to MPEG-2 TS packet formats. Then, the mobile servicemultiplexer 150 multiplexes the encapsulated TS packets, therebyoutputting the multiplexed packets to the TS packet multiplexer 162.Hereinafter, the data packet being outputted from the mobile servicemultiplexer 150 will be referred to as a mobile service data packet forsimplicity.

Alternatively, the mobile service multiplexer 150 receives andencapsulates an RS frame payload, which is generated by using at leastone type of compression-encoded mobile service data and the signalingtable information for mobile services, to MPEG-2 TS packet formats.Then, the mobile service multiplexer 150 multiplexes the encapsulated TSpackets, thereby outputting the multiplexed packets to the TS packetmultiplexer 162. Hereinafter, the data packet being outputted from themobile service multiplexer 150 will be referred to as a mobile servicedata packet for simplicity.

According to an embodiment of the present invention, the mobile servicemultiplexer 150 encapsulates an RS frame payload, which is inputted inany one of the formats shown in FIG. 15, FIG. 17( a), or FIG. 17( b), toa TS packet format.

At this point, the transmitter 200 requires identification informationin order to identify and process the main service data packet and themobile service data packet. Herein, the identification information mayuse values pre-decided in accordance with an agreement between thetransmitting system and the receiving system, or may be configured of aseparate set of data, or may modify predetermined location value with inthe corresponding data packet.

As an example of the present invention, a different packet identifier(PID) may be assigned to identify each of the main service data packetand the mobile service data packet. More specifically, by assigning aPID, which does not use for the main service data packet, to the mobileservice data packet, the transmitter 200 refers to a PID of data packetinputted, thereby can identify each of the main service data packet andthe mobile service data packet.

In another example, by modifying a synchronization data byte within aheader of the mobile service data, the service data packet may beidentified by using the synchronization data byte value of thecorresponding service data packet. For example, the synchronization byteof the main service data packet directly outputs the value decided bythe ISO/IEC 13818-1 standard (i.e., 0×47) without any modification. Thesynchronization byte of the mobile service data packet modifies andoutputs the value, thereby identifying the main service data packet andthe mobile service data packet. Conversely, the synchronization byte ofthe main service data packet is modified and outputted, whereas thesynchronization byte of the mobile service data packet is directlyoutputted without being modified, thereby enabling the main service datapacket and the mobile service data packet to be identified.

A plurality of methods may be applied in the method of modifying thesynchronization byte. For example, each bit of the synchronization bytemay be inverted, or only a portion of the synchronization byte may beinverted.

As described above, any type of identification information may be usedto identify the main service data packet and the mobile service datapacket. Therefore, the scope of the present invention is not limitedonly to the example set forth in the description of the presentinvention.

Meanwhile, a transport multiplexer used in the conventional digitalbroadcasting system may be used as the transport multiplexer 160according to the present invention. More specifically, in order tomultiplex the mobile service data and the main service data and totransmit the multiplexed data, the data rate of the main service islimited to a data rate of (19.39−K) Mbps. Then, K Mbps, whichcorresponds to the remaining data rate, is assigned as the data rate ofthe mobile service. Thus, the transport multiplexer which is alreadybeing used may be used as it is without any modification.

Herein, the transport multiplexer 160 multiplexes the main service datapacket being outputted from the main service multiplexer 161 and themobile service data packet being outputted from the mobile servicemultiplexer 150. Thereafter, the transport multiplexer 160 transmits themultiplexed data packets to the transmitter 200.

However, in some cases, the output data rate of the mobile servicemultiplexer 150 may not be equal to K Mbps. For example, when theservice multiplexer 100 assigns K Mbps of the 19.39 Mbps to the mobileservice data, and when the remaining (19.39−K) Mbps is, therefore,assigned to the main service data, the data rate of the mobile servicedata that are multiplexed by the service multiplexer 100 actuallybecomes lower than K Mbps. This is because, in case of the mobileservice data, the pre-processor of the transmitting system performsadditional encoding, thereby increasing the amount of data. Eventually,the data rate of the mobile service data, which may be transmitted fromthe service multiplexer 100, becomes smaller than K Mbps.

For example, since the pre-processor of the transmitter performs anencoding process on the mobile service data at a coding rate of at least½, the amount of the data outputted from the pre-processor is increasedto more than twice the amount of the data initially inputted to thepre-processor. Therefore, the sum of the data rate of the main servicedata and the data rate of the mobile service data, both beingmultiplexed by the service multiplexer 100, becomes either equal to orsmaller than 19.39 Mbps.

In order to set the final output data rate of the mobile servicemultiplexer 150 to K Mbps, the service multiplexer 100 of the presentinvention may perform various exemplary operations.

According to an embodiment of the present invention, the null packetgenerator 130 may generate a null data packet, which is then outputtedto the mobile service multiplexer 150. Thereafter, the mobile servicemultiplexer 150 may multiplex the null data packet and the mobileservice data packets, so as to set the output data rate to K Mbps.

At this point, the null data packet is transmitted to the transmitter200, thereby being discarded. More specifically, the null data packet isnot transmitted to the receiving system. In order to do so,identification information for identifying the null data is alsorequired. Herein, the identification information for identifying thenull data may also use a value pre-decided based upon an agreementbetween the transmitting system and the receiving system and may also beconfigured of a separate set of data. And, the identificationinformation for identifying the null data may also change apredetermined position value within the null data packet and use thechanged value. For example, the null packet generator 130 may modify (orchange) a synchronization byte value within the header of the null datapacket, thereby using the changed value as the identificationinformation. Alternatively, the transport_error_indicator flag may beset to ‘1’, thereby being used as the identification information.According to the embodiment of the present invention, thetransport_error_indicator flag within the header of the null data packetis used as the identification information for identifying the null datapacket. In this case, the transport_error_indicator flag of the nulldata packet is set to ‘1’, and the transport_error_indicator flag foreach of the other remaining data packets is reset to ‘0’, so that thenull data packet can be identified (or distinguished).

More specifically, when the null packet generator 130 generated a nulldata packet, and if, among the fields included in the header of the nulldata packet, the transport_error_indicator flag is set to ‘1’ and thentransmitted, the transmitter 200 may identify and discard the null datapacket corresponding to the transport_error_indicator flag.

Herein, any value that can identify the null data packet may be used asthe identification information for identifying the null data packet.Therefore, the present invention will not be limited only to the exampleproposed in the description of the present invention.

As another example of setting (or matching) the final output data rateof the mobile service multiplexer 150 to K Mbps, an operations andmaintenance (OM) packet (also referred to as OMP) may be used. In thiscase, the mobile service multiplexer 150 may multiplex the mobileservice data packet, the null data packet, and the OM packet, so as toset the output data rate to K Mbps.

Meanwhile, signaling data, such as transmission parameters, are requiredfor enabling the transmitter 200 to process the mobile service data.

According to an embodiment of the present invention, the transmissionparameter is inserted in the payload region of the OM packet, therebybeing transmitted to the transmitter.

At this point, in order to enable the transmitter 200 to identify theinsertion of the transmission parameter in the OM packet, identificationinformation that can identify the insertion of the transmissionparameter in the type field of the corresponding OM packet (i.e.,OM_type field).

More specifically, an operations and maintenance packet (OMP) is definedfor the purpose of operating and managing the transmitting system. Forexample, the OMP is configured in an MPEG-2 TS packet format, and thevalue of its respective PID is equal to ‘0x1FFA’. The OMP consists of a4-byte header and a 184-byte payload. Among the 184 bytes, the firstbyte corresponds to the OM_type field indicating the type of thecorresponding OM packet (OMP). And, the remaining 183 bytes correspondto an OM payload field, wherein actual data are inserted.

According to the present invention, among the reserved field values ofthe OM_type field, a pre-arranged value is used, thereby being capableof indicating that a transmission parameter has been inserted in thecorresponding OM packet. Thereafter, the transmitter 200 may locate (oridentify) the corresponding OMP by referring to the respective PID.Subsequently, by parsing the OM_type field within the OMP, thetransmitter 200 may be able to know (or recognize) whether or not atransmission parameter has been inserted in the corresponding OM packet.

The transmission parameters that can be transmitted to the OM packetinclude M/H frame information (e.g., M/H frame_index), FIC information(e.g., next_FIC_version_number), parade information (e.g.,number_of_parades, parade_id, parade_repetition_cycle, and ensemble_id),group information (e.g., number_of_group and start_group_number), SCCCinformation (e.g., SCCC_block_mode and SCCC_outer_code_mode), RS_frameinformation (e.g., RS_Frame_mode and RS_frame_continuity_counter), RSencoding information (e.g., RS_code_mode), and so on.

At this point, the OM packet in which the transmission parameter isinserted may be periodically generated by a constant cycle, so as to bemultiplexed with the mobile service data packet.

The multiplexing rules and the generation of null data packets of themobile service multiplexer 150, the main service multiplexer 161, andthe TS packet multiplexer 160 are controlled by the controller 110.

The TS packet multiplexer 162 multiplexes a data packet being outputtedfrom the main service multiplexer 161 at (19.39−K) Mbps with a datapacket being outputted from the mobile service multiplexer 150 at KMbps. Thereafter, the TS packet multiplexer 162 transmits themultiplexed data packet to the transmitter 200 at a data rate of 19.39Mbps.

Transmitter

FIG. 19 illustrates a block diagram showing an example of thetransmitter 200 according to an embodiment of the present invention.Herein, the transmitter 200 includes a controller 201, a demultiplexer210, a packet jitter mitigatori 220, a pre-processor 230, a packetmultiplexer 240, a post-processor 250, a synchronization (sync)multiplexer 260, and a transmission unit 270.

Herein, when a data packet is received from the service multiplexer 100,the demultiplexer 210 should identify whether the received data packetcorresponds to a main service data packet, a mobile service data packet,a null data packet, or an OM packet.

For example, the demultiplexer 210 uses the PID within the received datapacket so as to identify the main service data packet, the mobileservice data packet, and the null data packet. Then, the demultiplexer210 uses a transport_error_indicator field to identify the null datapacket.

If an OM packet is included in the received data packet, the OM packetmay identify using the PID within the received data packet. And by usingthe OM_type field included in the identified OM packet, thedemultiplexer 210 may be able to know whether or not a transmissionparameter is included in the payload region of the corresponding OMpacket and, then, received.

The main service data packet identified by the demultiplexer 210 isoutputted to the packet jitter mitigator 220, the mobile service datapacket is outputted to the pre-processor 230, and the null data packetis discarded. If the transmission parameter is included in the OMpacket, the corresponding transmission parameter is extracted, so as tobe outputted to the corresponding blocks. Thereafter, the OM packet isdiscarded. According to an embodiment of the present invention, thetransmission parameter extracted from the OM packet is outputted to thecorresponding blocks through the controller 201.

The pre-processor 230 performs an additional encoding process of themobile service data included in the service data packet, which isdemultiplexed and outputted from the demultiplexer 210. Thepre-processor 230 also performs a process of configuring a data group sothat the data group may be positioned at a specific place in accordancewith the purpose of the data, which are to be transmitted on atransmission frame. This is to enable the mobile service data to respondswiftly and strongly against noise and channel changes. Thepre-processor 230 may also refer to the transmission parameter extractedin the OM packet when performing the additional encoding process. Also,the pre-processor 230 groups a plurality of mobile service data packetsto configure a data group. Thereafter, known data, mobile service data,RS parity data, and MPEG header are allocated to pre-determined regionswithin the data group.

Pre-processor within Transmitter

FIG. 20 illustrates a block diagram showing the structure of apre-processor 230 according to the present invention. Herein, thepre-processor 230 includes an M/H frame encoder 301, a block processor302, a group formatter 303, a signaling encoder 304, and a packetformatter 305.

The M/H frame encoder 301, which is included in the pre-processor 230having the above-described structure, data-randomizes the mobile servicedata that are inputted to the demultiplexer 210, forms at least one RSframe belonging to an ensemble and performs encoding for errorcorrection by an RS frame unit.

The M/H frame encoder 301 may include at least one RS frame encoder.More specifically, RS frame encoders may be provided in parallel,wherein the number of RS frame encoders is equal to the number ofparades within the M/H frame. As described above, the M/H frame is abasic time cycle period for transmitting at least one parade. Also, eachparade consists of one or two RS frames.

FIG. 21 illustrates a conceptual block diagram of the M/H frame encoder301 according to an embodiment of the present invention. The M/H frameencoder 301 includes an input demultiplexer (DEMUX) 309, M number of RSframe encoders 310 to 31M−1, and an output multiplexer (MUX) 320.Herein, M represent the number of parades included in one M/H frame.

The demultiplexer 309 output the inputted mobile service data packet toa corresponding RS frame encoder among M number of RS frame encoders inensemble units.

At this point, an ensemble may be mapped into an RS frame or a parade.For example, if one parade is composed of one RS frame, an ensemble, anRS frame and a parade may be mapped at a 1:1:1, respectively.

According to an embodiment of the present invention, each RS frameencoder forms an RS frame payload using mobile service data inputted andperforms an error correction encoding process in RS frame payload units,thereby forming an RS frame. Also, each RS frame encoder divides theerror-correction-encoded RS frame into a plurality of portions, in orderto assign the error-correction-encoded RS frame data to a plurality ofdata groups. Based upon the RS frame mode of Table 1, data within one RSframe may be assigned either to all of regions A/B/C/D within multipledata groups, or to at least one of regions A/B and regions C/D withinmultiple data groups.

When the RS frame mode value is equal to ‘01’, i.e., when the data ofthe primary RS frame are assigned to regions A/B of the correspondingdata group and data of the secondary RS frame are assigned to regionsC/D of the corresponding data group, each RS frame encoder creates aprimary RS frame and a secondary RS frame for each parade. Conversely,when the RS frame mode value is equal to ‘00’, when the data of theprimary RS frame are assigned to all of regions A/B/C/D, each RS frameencoder creates a RS frame (i.e., a primary RS frame) for each parade.

Also, each RS frame encoder divides each RS frame into several portions.Each portion of the RS frame is equivalent to a data amount that can betransmitted by a data group. The output multiplexer (MUX) 320multiplexes portions within M number of RS frame encoders 310 to 310M−1are multiplexed and then outputted to the block processor 302.

For example, if one parade transmits two RS frames, portions of primaryRS frames within M number of RS frame encoders 310 to 310M−1 aremultiplexed and outputted. Thereafter, portions of secondary RS frameswithin M number of RS frame encoders 310 to 310M−1 are multiplexed andtransmitted.

The input demultiplexer (DEMUX) 309 and the output multiplexer (MUX) 320operate based upon the control of the controller 201. The controller 201may provide necessary (or required) FEC modes to each RS frame encoder.The FEC mode includes the RS code mode, which will be described indetail in a later process.

FIG. 22 illustrates a detailed block diagram of an RS frame encoderamong a plurality of RS frame encoders within an M/H frame encoder.

One RS frame encoder may include a primary encoder 410 and a secondaryencoder 420. Herein, the secondary encoder 420 may or may not operatebased upon the RS frame mode. For example, when the RS frame mode valueis equal to ‘00’, as shown in Table 1, the secondary encoder 420 doesnot operate.

The primary encoder 410 may include a data randomizer 411, aReed-Solomon-cyclic redundancy check (RS-CRC) encoder 412, and a RSframe divider 413. And, the secondary encoder 420 may also include adata randomizer 421, a RS-CRC encoder 422, and a RS frame divider 423.

More specifically, the data randomizer 411 of the primary encoder 410receives mobile service data of a primary RS frame payload belonging toa primary ensemble outputted from the output demultiplexer (DEMUX) 309.Then, after randomizing the received mobile service data, the datarandomizer 411 outputs the randomized data to the RS-CRC encoder 412. Atthis point, since the data randomizer 411 performs randomizing on themobile service data, the process of performing randomizing on the mobileservice data may be omitted from the data randomizer 251 of thepost-processor 250. The data randomizer 411 may perform randomizingafter removing synchronization bytes within the mobile service datapacket. Alternatively, the data randomizer 411 may also performrandomizing without removing the synchronization bytes. This is anoption that may be selected by the system designer. According to anexemplary embodiment of the present invention, the randomizing processwill be performed without data removing the synchronization bytes withinthe corresponding mobile service data packet.

The RS-CRC encoder 412 forms an RS frame payload belonging to therandomized primary ensemble, and performs forward error collection(FEC)-encoding in the RS frame payload unit using at least one of aReed-Solomon (RS) code and a cyclic redundancy check (CRC) code. TheRS-CRC encoder 412 outputs the FEC-encoded RS frame to the RS framedivider 413.

The RS-CRC encoder 412 groups a plurality of mobile service data that israndomized and inputted, so as to form a RS frame payload. Then, theRS-CRC encoder 412 performs at least one of an error correction encodingprocess and an error detection encoding process in RS frame payloadunits, thereby forming an RS frame. Accordingly, robustness may beprovided to the mobile service data, thereby scattering group error thatmay occur during changes in a frequency environment, thereby enablingthe mobile service data to respond to the frequency environment, whichis extremely vulnerable and liable to frequent changes. Also, the RS-CRCencoder 412 groups a plurality of RS frame so as to create a superframe, thereby performing a row permutation process in super frameunits. The row permutation process may also be referred to as a “rowinterleaving process”. Hereinafter, the process will be referred to as“row permutation” for simplicity. In the present invention, the rowpermutation process is optional.

More specifically, when the RS-CRC encoder 412 performs the process ofpermuting each row of the super frame in accordance with apre-determined rule, the position of the rows within the super framebefore and after the row permutation process is changed. If the rowpermutation process is performed by super frame units, and even thoughthe section having a plurality of errors occurring therein becomes verylong, and even though the number of errors included in the RS frame,which is to be decoded, exceeds the extent of being able to becorrected, the errors become dispersed within the entire super frame.Thus, the decoding ability is even more enhanced as compared to a singleRS frame.

At this point, as an example of the present invention, RS-encoding isapplied for the error correction encoding process, and a cyclicredundancy check (CRC) encoding is applied for the error detectionprocess in the RS-CRC encoder 412. When performing the RS-encoding,parity data that are used for the error correction are generated. And,when performing the CRC encoding, CRC data that are used for the errordetection are generated. The CRC data generated by CRC encoding may beused for indicating whether or not the mobile service data have beendamaged by the errors while being transmitted through the channel. Inthe present invention, a variety of error detection coding methods otherthan the CRC encoding method may be used, or the error correction codingmethod may be used to enhance the overall error correction ability ofthe receiving system.

Herein, the RS-CRC encoder 412 refers to a pre-determined transmissionparameter provided by the controller 201 so as to perform operationsincluding RS frame configuration, RS encoding, CRC encoding, super frameconfiguration, and row permutation in super frame units.

FIG. 23( a) and FIG. 23( b) illustrate a process of one or two RS framebeing divided into several portions, based upon an RS frame mode value,and a process of each portion being assigned to a corresponding regionwithin the respective data group. According to an embodiment of thepresent invention, the data assignment within the data group isperformed by the group formatter 303.

More specifically, FIG. 23( a) shows an example of the RS frame modevalue being equal to ‘00’. Herein, only the primary encoder 410 of FIG.22 operates, thereby forming one RS frame for one parade. Then, the RSframe is divided into several portions, and the data of each portion areassigned to regions A/B/C/D within the respective data group. FIG. 23(b) shows an example of the RS frame mode value being equal to ‘01’.Herein, both the primary encoder 410 and the secondary encoder 420 ofFIG. 22 operate, thereby forming two RS frames for one parade, i.e., oneprimary RS frame and one secondary RS frame. Then, the primary RS frameis divided into several portions, and the secondary RS frame is dividedinto several portions. At this point, the data of each portion of theprimary RS frame are assigned to regions A/B within the respective datagroup. And, the data of each portion of the secondary RS frame areassigned to regions C/D within the respective data group.

Detailed Description of the RS Frame

FIG. 24( a) illustrates an example of an RS frame being generated fromthe RS-CRC encoder 412 according to the present invention.

When the RS frame payload is formed, as shown in FIG. 24( a), the RS-CRCencoder 412 performs a (Nc,Kc)-RS encoding process on each column, so asto generate Nc−Kc(=P) number of parity bytes. Then, the RS-CRC encoder412 adds the newly generated P number of parity bytes after the verylast byte of the corresponding column, thereby creating a column of(187+P) bytes. Herein, as shown in FIG. 24( a), Kc is equal to 187(i.e., Kc=187), and Nc is equal to 187+P (i.e., Nc=187+P). Herein, thevalue of P may vary depending upon the RS code mode. Table 6 below showsan example of an RS code mode, as one of the RS encoding information.

TABLE 6 Number of RS code Parity Bytes mode RS code (P) 00 (211, 187) 2401 (223, 187) 36 10 (235, 187) 48 11 Reserved Reserved

Table 6 shows an example of 2 bits being assigned in order to indicatethe RS code mode. The RS code mode represents the number of parity bytescorresponding to the RS frame payload.

For example, when the RS code mode value is equal to ‘10’,(235,187)-RS-encoding is performed on the RS frame payload of FIG. 24(a), so as to generate 48 parity data bytes. Thereafter, the 48 paritybytes are added after the last data byte of the corresponding column,thereby creating a column of 235 data bytes.

When the RS frame mode value is equal to ‘00’ in Table 1 (i.e., when theRS frame mode indicates a single RS frame), only the RS code mode of thecorresponding RS frame is indicated. However, when the RS frame modevalue is equal to ‘01’ in Table 1 (i.e., when the RS frame modeindicates multiple RS frames), the RS code mode corresponding to aprimary RS frame and a secondary RS frame. More specifically, it ispreferable that the RS code mode is independently applied to the primaryRS frame and the secondary RS frame.

When such RS encoding process is performed on all N number of columns, asize of N(row)×(187+P) (column) bytes may be generated, as shown in FIG.24( b).

Each row of the RS frame payload is configured of N bytes. However,depending upon channel conditions between the transmitting system andthe receiving system, error may be included in the RS frame payload.When errors occur as described above, CRC data (or CRC code or CRCchecksum) may be used on each row unit in order to verify whether errorexists in each row unit.

The RS-CRC encoder 412 may perform CRC encoding on the mobile servicedata being RS encoded so as to create (or generate) the CRC data. TheCRC data being generated by CRC encoding may be used to indicate whetherthe mobile service data have been damaged while being transmittedthrough the channel.

The present invention may also use different error detection encodingmethods other than the CRC encoding method. Alternatively, the presentinvention may use the error correction encoding method to enhance theoverall error correction ability of the receiving system.

FIG. 24( c) illustrates an example of using a 2-byte (i.e., 16-bit) CRCchecksum as the CRC data. Herein, a 2-byte CRC checksum is generated forN number of bytes of each row, thereby adding the 2-byte CRC checksum atthe end of the N number of bytes. Thus, each row is expanded to (N+2)number of bytes. Equation 3 below corresponds to an exemplary equationfor generating a 2-byte CRC checksum for each row being configured of Nnumber of bytes.

g(x)=x ¹⁶ +x ¹² +x ⁵+1  Equation 3

The process of adding a 2-byte checksum in each row is only exemplary.Therefore, the present invention is not limited only to the exampleproposed in the description set forth herein. As described above, whenthe process of RS encoding and CRC encoding are completed, the(N×187)-byte RS frame payload is converted into a (N+2)×(187+P)-byte RSframe. Based upon an error correction scenario of a RS frame formed asdescribed above, the data bytes within the RS frame are transmittedthrough a channel in a row direction. At this point, when a large numberof errors occur during a limited period of transmission time, errorsalso occur in a row direction within the RS frame being processed with adecoding process in the receiving system. However, in the perspective ofRS encoding performed in a column direction, the errors are shown asbeing scattered. Therefore, error correction may be performed moreeffectively. At this point, a method of increasing the number of paritydata bytes (P) may be used in order to perform a more intense errorcorrection process. However, using this method may lead to a decrease intransmission efficiency. Therefore, a mutually advantageous method isrequired. Furthermore, when performing the decoding process, an erasuredecoding process may be used to enhance the error correctionperformance.

Additionally, the RS-CRC encoder 412 according to the present inventionalso performs a row permutation (or interleaving) process in super frameunits in order to further enhance the error correction performance whenerror correction the RS frame.

FIG. 25( a) to FIG. 25( d) illustrates an example of performing a rowpermutation process in super frame units according to the presentinvention. More specifically, G number of RS frames RS-CRC-encoded isgrouped to form a super frame, as shown in FIG. 25( a). At this point,since each RS frame is formed of (N+2)×(187+P) number of bytes, onesuper frame is configured to have the size of (N+2)×(187+P)×G bytes.

When a row permutation process permuting each row of the super frameconfigured as described above is performed based upon a pre-determinedpermutation rule, the positions of the rows prior to and after beingpermuted (or interleaved) within the super frame may be altered. Morespecifically, the i^(th) row of the super frame prior to theinterleaving process, as shown in FIG. 25( b), is positioned in thej^(th) row of the same super frame after the row permutation process, asshown in FIG. 25( c). The above-described relation between i and j canbe easily understood with reference to a permutation rule as shown inEquation 4 below.

j=G(i mod(187+P))+└i/(187+P)┘

i=(187+P)(j mod G)+└j/G┘

-   -   where 0≦i, j (187+P)G−1; or    -   where 0, j<(187+P)G

Herein, each row of the super frame is configured of (N+2) number ofdata bytes even after being row-permuted in super frame units.

When all row permutation processes in super frame units are completed,the super frame is once again divided into G number of row-permuted RSframes, as shown in FIG. 25( d), and then provided to the RS framedivider 413. Herein, the number of RS parity bytes and the number ofcolumns should be equally provided in each of the RS frames, whichconfigure a super frame. As described in the error correction scenarioof a RS frame, in case of the super frame, a section having a largenumber of error occurring therein is so long that, even when one RSframe that is to be decoded includes an excessive number of errors(i.e., to an extent that the errors cannot be corrected), such errorsare scattered throughout the entire super frame. Therefore, incomparison with a single RS frame, the decoding performance of the superframe is more enhanced.

The above description of the present invention corresponds to theprocesses of forming (or creating) and encoding an RS frame, when a datagroup is divided into regions A/B/C/D, and when data of an RS frame areassigned to all of regions A/B/C/D within the corresponding data group.More specifically, the above description corresponds to an embodiment ofthe present invention, wherein one RS frame is transmitted using oneparade. In this embodiment, the secondary encoder 420 does not operate(or is not active).

Meanwhile, 2 RS frames are transmitting using one parade, the data ofthe primary RS frame may be assigned to regions A/B within the datagroup and be transmitted, and the data of the secondary RS frame may beassigned to regions C/D within the data group and be transmitted. Atthis point, the primary encoder 410 receives the mobile service datathat are to be assigned to regions A/B within the data group, forms theprimary RS frame payload, and then performs RS-encoding and CRC-encodingon the primary RS frame payload, thereby forming the primary RS frame.Similarly, the secondary encoder 420 receives the mobile service datathat are to be assigned to regions C/D within the data group, forms thesecondary RS frame payload, and then performs RS-encoding andCRC-encoding on the secondary RS frame payload thereby forming thesecondary RS frame. More specifically, the primary RS frame and thesecondary RS frame are generated independently.

FIG. 26 illustrates examples of receiving the mobile service data thatare to be assigned to regions A/B within the data group, so as to formthe primary RS frame payload, and receives the mobile service data thatare to be assigned to regions C/D within the data group, so as to formthe secondary RS frame payload, thereby performing error correctionencoding and error detection encoding on each of the first and secondaryRS frame payloads.

More specifically, FIG. 26( a) illustrates an example of the RS-CRCencoder 412 of the primary encoder 410 receiving mobile service data ofthe primary ensemble that are to be assigned to regions A/B within thecorresponding data group, so as to create an RS frame payload having thesize of N1(row)×187(column). Then, in this example, the primary encoder410 performs RS-encoding on each column of the RS frame payload createdas described above, thereby adding P1 number of parity data bytes ineach column. Finally, the primary encoder 410 performs CRC-encoding oneach row, thereby adding a 2-byte checksum in each row, thereby formingan primary RS frame.

FIG. 26( b) illustrates an example of the RS-CRC encoder 422 of thesecondary encoder 420 receiving mobile service data of the secondaryensemble that are to be assigned to regions C/D within the correspondingdata group, so as to create an RS frame payload having the size ofN2(row)×187(column). Then, in this example, the secondary encoder 420performs RS-encoding on each column of the RS frame payload created asdescribed above, thereby adding P2 number of parity data bytes in eachcolumn. Finally, the secondary encoder 420 performs CRC-encoding on eachrow, thereby adding a 2-byte checksum in each row, thereby forming ansecondary RS frame.

At this point, each of the RS-CRC encoders 412 and 422 may refer to apre-determined transmission parameter provided by the controller 201,the RS-CRC encoders 412 and 422 may be informed of M/H frameinformation, FIC information, RS frame information (including RS framemode information), RS encoding information (including RS code mode),SCCC information (including SCCC block mode information and SCCC outercode mode information), data group information, and region informationwithin a data group. The RS-CRC encoders 412 and 422 may refer to thetransmission parameters for the purpose of RS frame configuration, errorcorrection encoding, error detection encoding. Furthermore, thetransmission parameters should also be transmitted to the receivingsystem so that the receiving system can perform a normal decodingprocess. At this point, as an example of the present invention, thetransmission parameter is transmitted through transmission parameterchannel (TPC) to a receiving system. The TPC will be described in detailin a later.

The data of the primary RS frame, which is encoded by RS frame units androw-permuted by super frame units from the RS-CRC encoder 412 of theprimary encoder 410, are outputted to the RS frame divider 413. If thesecondary encoder 420 also operates in the embodiment of the presentinvention, the data of the secondary RS frame, which is encoded by RSframe units and row-permuted by super frame units from the RS-CRCencoder 422 of the secondary encoder 420, are outputted to the RS framedivider 423. The RS frame divider 413 of the primary encoder 410 dividesthe primary RS frame into several portions, which are then outputted tothe output multiplexer (MUX) 320. Each portion of the primary RS frameis equivalent to a data amount that can be transmitted by one datagroup. Similarly, the RS frame divider 423 of the secondary encoder 420divides the secondary RS frame into several portions, which are thenoutputted to the output multiplexer (MUX) 320.

Hereinafter, the RS frame divider 413 of the primary RS encoder 410 willnow be described in detail. Also, in order to simplify the descriptionof the present invention, it is assumed that an RS frame payload havingthe size of N(row)×187(column), as shown in FIG. 24( a) to FIG. 24( c),that P number of parity data bytes are added to each column byRS-encoding the RS frame payload, and that a 2-byte checksum is added toeach row by CRC-encoding the RS frame payload. As a result, an RS framehaving the size of (N+2) (row)×187+P (column) is formed. Accordingly,the RS frame divider 413 divides (or partitions) the RS frame having thesize of (N+2) (row)×187+P (column) into several portions, each havingthe size of PL (wherein PL corresponds to the length of the RS frameportion).

At this point, as shown in Table 2 to Table 5, the value of PL may varydepending upon the RS frame mode, SCCC block mode, and SCCC outer codermode. Also, the total number of data bytes of the RS-encoded andCRC-encoded RS frame is equal to or smaller than 5×NoG×PL . In thiscase, the RS frame is divided (or partitioned) into ((5×NoG)−1) numberof portions each having the size of PL and one portion having a sizeequal to smaller than PL. More specifically, with the exception of thelast portion of the RS frame, each of the remaining portions of the RSframe has an equal size of PL. If the size of the last portion issmaller than PL, a stuffing byte (or dummy byte) may be inserted inorder to fill (or replace) the lacking number of data bytes, therebyenabling the last portion of the RS frame to also be equal to PL. Eachportion of an RS frame corresponds to the amount of data that are to beSCCC-encoded and mapped into a single data group of a parade.

FIG. 27( a) and FIG. 27( b) respectively illustrate examples of adding Snumber of stuffing bytes, when an RS frame having the size of(N+2)(row)×(187+P)(column) is divided into 5×NoG number of portions,each having the size of PL. More specifically, the RS-encoded andCRC-encoded RS frame, shown in FIG. 27( a), is divided into severalportions, as shown in FIG. 27( b). The number of divided portions at theRS frame is equal to (5×NoG). Particularly, the first ((5×NoG)−1) numberof portions each has the size of PL, and the last portion of the RSframe may be equal to or smaller than PL. If the size of the lastportion is smaller than PL, a stuffing byte (or dummy byte) may beinserted in order to fill (or replace) the lacking number of data bytes,as shown in Equation 5 below, thereby enabling the last portion of theRS frame to also be equal to PL.

S=(5×NoG×PL)−((N+2)×(187+P))

Herein, each portion including data having the size of PL passes throughthe output multiplexer 320 of the M/H frame encoder 301, which is thenoutputted to the block processor 302.

At this point, the mapping order of the RS frame portions to a parade ofdata groups in not identical with the group assignment order defined inEquation 1. When given the group positions of a parade in an M/H frame,the SCCC-encoded RS frame portions will be mapped in a time order (i.e.,in a left-to-right direction).

For example, as shown in FIG. 11, data groups of the 2^(nd) parade(Parade #1) are first assigned (or allocated) to the 13^(th) slot (Slot#12) and then assigned to the 3^(rd) slot (Slot #2). However, when thedata are actually placed in the assigned slots, the data are placed in atime sequence (or time order, i.e., in a left-to-right direction). Morespecifically, the 1^(st) data group of Parade #1 is placed in Slot #2,and the 2^(nd) data group of Parade #1 is placed in Slot #12.

Block Processor

Meanwhile, the block processor 302 performs an SCCC outer encodingprocess on the output of the M/H frame encoder 301. More specifically,the block processor 302 receives the data of each error correctionencoded portion. Then, the block processor 302 encodes the data onceagain at a coding rate of 1/H (wherein H is an integer equal to orgreater than 2 (i.e., H≧2)), thereby outputting the 1/H-rate encodeddata to the group formatter 303. According to the embodiment of thepresent invention, the input data are encoded either at a coding rate of½ (also referred to as “½-rate encoding”) or at a coding rate of ¼ (alsoreferred to as “¼-rate encoding”). The data of each portion outputtedfrom the M/H frame encoder 301 may include at least one of mobileservice data, RS parity data, CRC data, and stuffing data. However, in abroader meaning, the data included in each portion may correspond todata for mobile services. Therefore, the data included in each portionwill all be considered as mobile service data and described accordingly.

The group formatter 303 inserts the mobile service dataSCCC-outer-encoded and outputted from the block processor 302 in thecorresponding region within the data group, which is formed inaccordance with a pre-defined rule. Also, in association with the datadeinterleaving process, the group formatter 303 inserts various placeholders (or known data place holders) in the corresponding region withinthe data group. Thereafter, the group formatter 303 deinterleaves thedata within the data group and the place holders.

According to the present invention, with reference to data after beingdata-interleaved, as shown in FIG. 5, a data groups is configured of 10M/H blocks (B1 to B10) and divided into 4 regions (A, B, C, and D).Also, as shown in FIG. 5, when it is assumed that the data group isdivided into a plurality of hierarchical regions, as described above,the block processor 302 may encode the mobile service data, which are tobe inserted to each region based upon the characteristic of eachhierarchical region, at different coding rates. For example, the blockprocessor 302 may encode the mobile service data, which are to beinserted in region A/B within the corresponding data group, at a codingrate of ½. Then, the group formatter 303 may insert the ½-rate encodedmobile service data to region A/B. Also, the block processor 302 mayencode the mobile service data, which are to be inserted in region C/Dwithin the corresponding data group, at a coding rate of ¼ having higher(or stronger) error correction ability than the ½-coding rate.Thereafter, the group formatter 303 may insert the ½-rate encoded mobileservice data to region C/D. In another example, the block processor 302may encode the mobile service data, which are to be inserted in regionC/D, at a coding rate having higher error correction ability than the¼-coding rate. Then, the group formatter 303 may either insert theencoded mobile service data to region C/D, as described above, or leavethe data in a reserved region for future usage.

According to another embodiment of the present invention, the blockprocessor 302 may perform a 1/H-rate encoding process in SCCC blockunits. Herein, the SCCC block includes at least one M/H block. At thispoint, when 1/H-rate encoding is performed in M/H block units, the M/Hblocks (B1 to B10) and the SCCC block (SCB1 to SCB10) become identicalto one another (i.e., SCB1=B1, SCB2=B2, SCB3=B3, SCB4=B4, SCB5=B5,SCB6=B6, SCB7=B7, SCB8=B8, SCB9=B9, and SCB10=B10). For example, the M/Hblock 1 (B1) may be encoded at the coding rate of ½, the M/H block 2(B2) may be encoded at the coding rate of ¼, and the M/H block 3 (B3)may be encoded at the coding rate of ½. The coding rates are appliedrespectively to the remaining M/H blocks.

Alternatively, a plurality of M/H blocks within regions A, B, C, and Dmay be grouped into one SCCC block, thereby being encoded at a codingrate of 1/H in SCCC block units. Accordingly, the receiving performanceof region C/D may be enhanced. For example, M/H block 1 (B1) to M/Hblock 5 (B5) may be grouped into one SCCC block and then encoded at acoding rate of ½. Thereafter, the group formatter 303 may insert the½-rate encoded mobile service data to a section starting from M/H block1 (B1) to M/H block 5 (B5). Furthermore, M/H block 6 (B6) to M/H block10 (B10) may be grouped into one SCCC block and then encoded at a codingrate of ¼. Thereafter, the group formatter 303 may insert the ¼-rateencoded mobile service data to another section starting from M/H block 6(B6) to M/H block 10 (B10). In this case, one data group may consist oftwo SCCC blocks.

According to another embodiment of the present invention, one SCCC blockmay be formed by grouping two M/H blocks. For example, M/H block 1 (B1)and M/H block 6 (B6) may be grouped into one SCCC block (SCB1).Similarly, M/H block 2 (B2) and M/H block 7 (B7) may be grouped intoanother SCCC block (SCB2). Also, M/H block 3 (B3) and M/H block 8 (B8)may be grouped into another SCCC block (SCB3). And, M/H block 4 (B4) andM/H block 9 (B9) may be grouped into another SCCC block (SCB4).Furthermore, M/H block 5 (B5) and M/H block 10 (B10) may be grouped intoanother SCCC block (SCB5). In the above-described example, the datagroup may consist of 10 M/H blocks and 5 SCCC blocks. Accordingly, in adata (or signal) receiving environment undergoing frequent and severechannel changes, the receiving performance of regions C and D, which isrelatively more deteriorated than the receiving performance of region A,may be reinforced. Furthermore, since the number of mobile service datasymbols increases more and more from region A to region D, the errorcorrection encoding performance becomes more and more deteriorated.Therefore, when grouping a plurality of M/H block to form one SCCCblock, such deterioration in the error correction encoding performancemay be reduced.

As described-above, when the block processor 302 performs encoding at a1/H-coding rate, information associated with SCCC should be transmittedto the receiving system in order to accurately recover the mobileservice data. Table 7 below shows an example of a SCCC block mode, whichindicating the relation between an M/H block and an SCCC block, amongdiverse SCCC block information.

TABLE 7 SCCC Block Mode 00 01 10 11 Description One M/H Two M/H BlockBlocks per SCCC per SCCC Block Block SCB input, SCB input, SCB M/H BlockM/H Blocks Reserved Reserved SCB1 B1 B1 + B6 SCB2 B2 B2 + B7 SCB3 B3B3 + B8 SCB4 B4 B4 + B9 SCB5 B5 B5 + B10 SCB6 B6 — SCB7 B7 — SCB8 B8 —SCB9 B9 — SCB10 B10 —

More specifically, Table 4 shows an example of 2 bits being allocated inorder to indicate the SCCC block mode. For example, when the SCCC blockmode value is equal to ‘00’, this indicates that the SCCC block and theM/H block are identical to one another. Also, when the SCCC block modevalue is equal to ‘01’, this indicates that each SCCC block isconfigured of 2 M/H blocks.

As described above, if one data group is configured of 2 SCCC blocks,although it is not indicated in Table 7, this information may also beindicated as the SCCC block mode. For example, when the SCCC block modevalue is equal to ‘10’, this indicates that each SCCC block isconfigured of 5 M/H blocks and that one data group is configured of 2SCCC blocks. Herein, the number of M/H blocks included in an SCCC blockand the position of each M/H block may vary depending upon the settingsmade by the system designer. Therefore, the present invention will notbe limited to the examples given herein. Accordingly, the SCCC modeinformation may also be expanded.

An example of a coding rate information of the SCCC block, i.e., SCCCouter code mode, is shown in Table 8 below.

TABLE 8 SCCC outer code mode (2 bits) Description 00 Outer code rate ofSCCC block is ½ rate 01 Outer code rate of SCCC block is ¼ rate 10Reserved 11 Reserved

More specifically, Table 8 shows an example of 2 bits being allocated inorder to indicate the coding rate information of the SCCC block. Forexample, when the SCCC outer code mode value is equal to ‘00’, thisindicates that the coding rate of the corresponding SCCC block is ½.And, when the SCCC outer code mode value is equal to ‘01’, thisindicates that the coding rate of the corresponding SCCC block is ¼.

If the SCCC block mode value of Table 7 indicates ‘00’, the SCCC outercode mode may indicate the coding rate of each M/H block with respect toeach M/H block. In this case, since it is assumed that one data groupincludes 10 M/H blocks and that 2 bits are allocated for each SCCC blockmode, a total of 20 bits are required for indicating the SCCC blockmodes of the 10 M/H modes. In another example, when the SCCC block modevalue of Table 7 indicates ‘00’, the SCCC outer code mode may indicatethe coding rate of each region with respect to each region within thedata group. In this case, since it is assumed that one data groupincludes 4 regions (i.e., regions A, B, C, and D) and that 2 bits areallocated for each SCCC block mode, a total of 8 bits are required forindicating the SCCC block modes of the 4 regions. In another example,when the SCCC block mode value of Table 7 is equal to ‘01’, each of theregions A, B, C, and D within the data group has the same SCCC outercode mode.

Meanwhile, an example of an SCCC output block length (SOBL) for eachSCCC block, when the SCCC block mode value is equal to ‘00’, is shown inTable 9 below.

TABLE 9 SIBL ½ ¼ SCCC Block SOBL rate rate SCB1 (B1) 528 264 132 SCB2(B2) 1536 768 384 SCB3 (B3) 2376 1188 594 SCB4 (B4) 2388 1194 597 SCB5(B5) 2772 1386 693 SCB6 (B6) 2472 1236 618 SCB7 (B7) 2772 1386 693 SCB8(B8) 2508 1254 627 SCB9 (B9) 1416 708 354 SCB10 (B10) 480 240 120

More specifically, when given the SCCC output block length (SOBL) foreach SCCC block, an SCCC input block length (SIBL) for eachcorresponding SCCC block may be decided based upon the outer coding rateof each SCCC block. The SOBL is equivalent to the number of SCCC output(or outer-encoded) bytes for each SCCC block. And, the SIBL isequivalent to the number of SCCC input (or payload) bytes for each SCCCblock. Table 10 below shows an example of the SOBL and SIBL for eachSCCC block, when the SCCC block mode value is equal to ‘01’.

TABLE 10 SIBL ½ ¼ SCCC Block SOBL rate rate SCB1 (B1 + B6) 528 264 132SCB2 (B2 + B7) 1536 768 384 SCB3 (B3 + B8) 2376 1188 594 SCB4 (B4 + B9)2388 1194 597 SCB5 (B5 + B10) 2772 1386 693

In order to do so, as shown in FIG. 28, the block processor 302 includesa RS frame portion-SCCC block converter 511, a byte-bit converter 512, aconvolution encoder 513, a symbol interleaver 514, a symbol-byteconverter 515, and an SCCC block-M/H block converter 516. Theconvolutional encoder 513 and the symbol interleaver 514 are virtuallyconcatenated with the trellis encoding module in the post-processor inorder to configure an SCCC block. More specifically, the RS frameportion-SCCC block converter 511 divides the RS frame portions, whichare being inputted, into multiple SCCC blocks using the SIBL of Table 9and Table 10 based upon the RS code mode, SCCC block mode, and SCCCouter code mode. Herein, the M/H frame encoder 301 may output onlyprimary RS frame portions or both primary RS frame portions andsecondary RS frame portions in accordance with the RS frame mode.

When the RS Frame mode is set to ‘00’, a portion of the primary RS Frameequal to the amount of data, which are to be SCCC outer encoded andmapped to 10 M/H blocks (B1 to B10) of a data group, will be provided tothe block processor 302. When the SCCC block mode value is equal to‘00’, then the primary RS frame portion will be split into 10 SCCCBlocks according to Table 9. Alternatively, when the SCCC block modevalue is equal to ‘01’, then the primary RS frame will be split into 5SCCC blocks according to Table 10.

When the RS frame mode value is equal to ‘01’, then the block processor302 may receive two RS frame portions. The RS frame mode value of ‘01’will not be used with the SCCC block mode value of ‘01’. The firstportion from the primary RS frame will be SCCC-outer-encoded as SCCCBlocks SCB3, SCB4, SCB5, SCB6, SCB7, and SCB8 by the block processor302. The SCCC Blocks SCB3 and SCB8 will be mapped to region B and theSCCC blocks SCB4, SCB5, SCB6, and SCB7 shall be mapped to region A bythe group formatter 303. The second portion from the secondary RS framewill also be SCCC-outer-encoded, as SCB1, SCB2, SCB9, and SCB10, by theblock processor 302. The group formatter 303 will map the SCCC blocksSCB1 and SCB10 to region D as the M/H blocks B1 and B10, respectively.Similarly, the SCCC blocks SCB2 and SCB9 will be mapped to region C asthe M/H blocks B2 and B9.

The byte-bit converter 512 identifies the mobile service data bytes ofeach SCCC block outputted from the RS frame portion-SCCC block converter511 as data bits, which are then outputted to the convolution encoder513. The convolution encoder 513 performs one of ½-rate encoding and¼-rate encoding on the inputted mobile service data bits.

FIG. 29 illustrates a detailed block diagram of the convolution encoder513. The convolution encoder 513 includes two delay units 521 and 523and three adders 522, 524, and 525. Herein, the convolution encoder 513encodes an input data bit U and outputs the coded bit U to 5 bits (u0 tou4). At this point, the input data bit U is directly outputted asuppermost bit u0 and simultaneously encoded as lower bit u1u2u3u4 andthen outputted. More specifically, the input data bit U is directlyoutputted as the uppermost bit u0 and simultaneously outputted to thefirst and third adders 522 and 525.

The first adder 522 adds the input data bit U and the output bit of thefirst delay unit 521 and, then, outputs the added bit to the seconddelay unit 523. Then, the data bit delayed by a pre-determined time(e.g., by 1 clock) in the second delay unit 523 is outputted as a lowerbit u1 and simultaneously fed-back to the first delay unit 521. Thefirst delay unit 521 delays the data bit fed-back from the second delayunit 523 by a pre-determined time (e.g., by 1 clock). Then, the firstdelay unit 521 outputs the delayed data bit as a lower bit u2 and, atthe same time, outputs the fed-back data to the first adder 522 and thesecond adder 524. The second adder 524 adds the data bits outputted fromthe first and second delay units 521 and 523 and outputs the added databits as a lower bit u3. The third adder 525 adds the input data bit Uand the output of the second delay unit 523 and outputs the added databit as a lower bit u4.

At this point, the first and second delay units 521 and 523 are reset to‘0’, at the starting point of each SCCC block. The convolution encoder513 of FIG. 29 may be used as a ½-rate encoder or a ¼-rate encoder. Morespecifically, when a portion of the output bit of the convolutionencoder 513, shown in FIG. 29, is selected and outputted, theconvolution encoder 513 may be used as one of a ½-rate encoder and a¼-rate encoder. Table 11 below shown an example of output symbols of theconvolution encoder 513.

TABLE 11 ¼ rate ½ SCCC block SCCC block Region rate mode = ‘00’ mode =‘01’ A, B (u0, (u0, u2), (u1, (u0, u2), u1) u3) (u1, u4) C, D (u0, u1),(u3, u4)

For example, at the ½-coding rate, 1 output symbol (i.e., u0 and u1bits) may be selected and outputted. And, at the ¼-coding rate,depending upon the SCCC block mode, 2 output symbols (i.e., 4 bits) maybe selected and outputted. For example, when the SCCC block mode valueis equal to ‘01’, and when an output symbol configured of u0 and u2 andanother output symbol configured of u1 and u4 are selected andoutputted, a ¼-rate coding result may be obtained.

The mobile service data encoded at the coding rate of ½ or ¼ by theconvolution encoder 513 are outputted to the symbol interleaver 514. Thesymbol interleaver 514 performs block interleaving, in symbol units, onthe output data symbol of the convolution encoder 513. Morespecifically, the symbol interleaver 514 is a type of block interleaver.Any interleaver performing structural rearrangement (or realignment) maybe applied as the symbol interleaver 514 of the block processor.However, in the present invention, a variable length symbol interleaverthat can be applied even when a plurality of lengths is provided for thesymbol, so that its order may be rearranged, may also be used.

FIG. 30 illustrates a symbol interleaver according to an embodiment ofthe present invention. Particularly, FIG. 30 illustrates an example ofthe symbol interleaver when B=2112 and L=4096. Herein, B indicates ablock length in symbols that are outputted for symbol interleaving fromthe convolution encoder 513. And, L represents a block length in symbolsthat are actually interleaved by the symbol interleaver 514. At thispoint, the block length in symbols B inputted to the symbol interleaver514 is equivalent to 4×SOBL. More specifically, since one symbol isconfigured of 2 bits, the value of B may be set to be equal to 4×SOBL.

In the present invention, when performing the symbol-interleavingprocess, the conditions of L=2^(m) (wherein m is an integer) and of L≧Bshould be satisfied. If there is a difference in value between B and L,(L−B) number of null (or dummy) symbols is added, thereby creating aninterleaving pattern, as shown in P′(i) of FIG. 30. Therefore, B becomesa block size of the actual symbols that are inputted to the symbolinterleaver 514 in order to be interleaved. L becomes an interleavingunit when the interleaving process is performed by an interleavingpattern created from the symbol interleaver 514.

Equation 6 shown below describes the process of sequentially receiving Bnumber of symbols, the order of which is to be rearranged, and obtainingan L value satisfying the conditions of L=2^(m) (wherein m is aninteger) and of L≧B, thereby creating the interleaving so as to realign(or rearrange) the symbol order.

In relation to all places, wherein 0≦i≦B−1,

P′(i)={89×i×(i+1)/2} mod L  Equation 6

Herein, L≧B, L=2^(m), wherein m is an integer.

As shown in P′ (i) of FIG. 30, the order of B number of input symbolsand (L−B) number of null symbols is rearranged by using theabove-mentioned Equation 6. Then, as shown in P(i) of FIG. 30, the nullbyte places are removed, so as to rearrange the order. Starting with thelowest value of i, the P(i) are shifted to the left in order to fill theempty entry locations. Thereafter, the symbols of the alignedinterleaving pattern P(i) are outputted to the symbol-byte converter 515in order. Herein, the symbol-byte converter 515 converts to bytes themobile service data symbols, having the rearranging of the symbol ordercompleted and then outputted in accordance with the rearranged order,and thereafter outputs the converted bytes to the SCCC block-M/H blockconverter 516. The SCCC block-M/H block converter 516 converts thesymbol-interleaved SCCC blocks to M/H blocks, which are then outputtedto the group formatter 303.

If the SCCC block mode value is equal to ‘00’, the SCCC block is mappedat a one-to-one (1:1) correspondence with each M/H block within the datagroup. In another example, if the SCCC block mode value is equal to‘01’, each SCCC block is mapped with two M/H blocks within the datagroup. For example, the SCCC block SCB1 is mapped with (B1, B6), theSCCC block SCB2 is mapped with (B2, B7), the SCCC block SCB3 is mappedwith (B3, B8), the SCCC block SCB4 is mapped with (B4, B9), and the SCCCblock SCB5 is mapped with (B5, B10). The M/H block that is outputtedfrom the SCCC block-M/H block converter 516 is configured of mobileservice data and FEC redundancy. In the present invention, the mobileservice data as well as the FEC redundancy of the M/H block will becollectively considered as mobile service data.

Group Formatter

The group formatter 303 inserts data of M/H blocks outputted from theblock processor 302 to the corresponding M/H blocks within the datagroup, which is formed in accordance with a pre-defined rule. Also, inassociation with the data-deinterleaving process, the group formatter303 inserts various place holders (or known data place holders) in thecorresponding region within the data group. More specifically, apartfrom the encoded mobile service data outputted from the block processor302, the group formatter 303 also inserts MPEG header place holders,non-systematic RS parity place holders, main service data place holders,which are associated with the data deinterleaving in a later process, asshown in FIG. 5.

Herein, the main service data place holders are inserted because themobile service data bytes and the main service data bytes arealternately mixed with one another in regions B to D based upon theinput of the data deinterleaver, as shown in FIG. 5. For example, basedupon the data outputted after data deinterleaving, the place holder forthe MPEG header may be allocated at the very beginning of each packet.Also, in order to configure an intended group format, dummy bytes mayalso be inserted. Furthermore, the group formatter 303 insertsinitialization data (i.e., trellis initialization byte) of the trellisencoding module 256 in the corresponding regions. For example, theinitialization data may be inserted in the beginning of the known datasequence. The initialization data is used for initializing memorieswithin the trellis encoding module 256, and is not transmitted to thereceiving system.

Additionally, the group formatter 303 may also insert signalinginformation, which are encoded and outputted from the signaling encoder304, in corresponding regions within the data group. At this point,reference may be made to the signaling information when the groupformatter 303 inserts each data type and respective place holders in thedata group. The process of encoding the signaling information andinserting the encoded signaling information to the data group will bedescribed in detail in a later process.

After inserting each data type and respective place holders in the datagroup, the group formatter 303 may deinterleaver the data and respectiveplace holders, which have been inserted in the data group, as an inverseprocess of the data interleaver, thereby outputting the deinterleaveddata and respective place holders to the packet formatter 305. The groupformatter 303 may include a group format organizer 527, and a datadeinterleaver 529, as shown in FIG. 31. The group format organizer 527inserts data and respective place holders in the corresponding regionswithin the data group, as described above. And, the data deinterleaver529 deinterleaves the inserted data and respective place holders as aninverse process of the data interleaver.

The packet formatter 305 removes the main service data place holders andthe RS parity place holders that were allocated for the deinterleavingprocess from the deinterleaved data being inputted. Then, the packetformatter 305 groups the remaining portion and inserts the 3-byte MPEGheader place holder in an MPEG header having a null packet PID (or anunused PID from the main service data packet). Furthermore, the packetformatter 305 adds a synchronization data byte at the beginning of each187-byte data packet. Also, when the group formatter 303 inserts knowndata place holders, the packet formatter 303 may insert actual knowndata in the known data place holders, or may directly output the knowndata place holders without any modification in order to make replacementinsertion in a later process. Thereafter, the packet formatter 305identifies the data within the packet-formatted data group, as describedabove, as a 188-byte unit mobile service data packet (i.e., MPEG TSpacket), which is then provided to the packet multiplexer 240.

Based upon the control of the controller 201, the packet multiplexer 240multiplexes the data group packet-formatted and outputted from thepacket formatter 306 and the main service data packet outputted from thepacket jitter mitigator 220. Then, the packet multiplexer 240 outputsthe multiplexed data packets to the data randomizer 251 of thepost-processor 250. More specifically, the controller 201 controls thetime-multiplexing of the packet multiplexer 240. If the packetmultiplexer 240 receives 118 mobile service data packets from the packetformatter 305, 37 mobile service data packets are placed before a placefor inserting VSB field synchronization. Then, the remaining 81 mobileservice data packets are placed after the place for inserting VSB fieldsynchronization. The multiplexing method may be adjusted by diversevariables of the system design. The multiplexing method and multiplexingrule of the packet multiplexer 240 will be described in more detail in alater process.

Also, since a data group including mobile service data in-between thedata bytes of the main service data is multiplexed (or allocated) duringthe packet multiplexing process, the shifting of the chronologicalposition (or place) of the main service data packet becomes relative.Also, a system object decoder (i.e., MPEG decoder) for processing themain service data of the receiving system, receives and decodes only themain service data and recognizes the mobile service data packet as anull data packet.

Therefore, when the system object decoder of the receiving systemreceives a main service data packet that is multiplexed with the datagroup, a packet jitter occurs.

At this point, since a multiple-level buffer for the video data existsin the system object decoder and the size of the buffer is relativelylarge, the packet jitter generated from the packet multiplexer 240 doesnot cause any serious problem in case of the video data. However, sincethe size of the buffer for the audio data in the object decoder isrelatively small, the packet jitter may cause considerable problem. Morespecifically, due to the packet jitter, an overflow or underflow mayoccur in the buffer for the main service data of the receiving system(e.g., the buffer for the audio data). Therefore, the packet jittermitigator 220 re-adjusts the relative position of the main service datapacket so that the overflow or underflow does not occur in the systemobject decoder.

In the present invention, examples of repositioning places for the audiodata packets within the main service data in order to minimize theinfluence on the operations of the audio buffer will be described indetail. The packet jitter mitigator 220 repositions the audio datapackets in the main service data section so that the audio data packetsof the main service data can be as equally and uniformly aligned andpositioned as possible. Additionally, when the positions of the mainservice data packets are relatively re-adjusted, associated programclock reference (PCR) values may also be modified accordingly. The PCRvalue corresponds to a time reference value for synchronizing the timeof the MPEG decoder. Herein, the PCR value is inserted in a specificregion of a TS packet and then transmitted.

In the example of the present invention, the packet jitter mitigator 220also performs the operation of modifying the PCR value. The output ofthe packet jitter mitigator 220 is inputted to the packet multiplexer240. As described above, the packet multiplexer 240 multiplexes the mainservice data packet outputted from the packet jitter mitigator 220 withthe mobile service data packet outputted from the pre-processor 230 intoa burst structure in accordance with a pre-determined multiplexing rule.Then, the packet multiplexer 240 outputs the multiplexed data packets tothe data randomizer 251 of the post-processor 250.

If the inputted data correspond to the main service data packet, thedata randomizer 251 performs the same randomizing process as that of theconventional randomizer. More specifically, the synchronization bytewithin the main service data packet is deleted. Then, the remaining 187data bytes are randomized by using a pseudo random byte generated fromthe data randomizer 251. Thereafter, the randomized data are outputtedto the RS encoder/non-systematic RS encoder 252. However, when theinputted data correspond to a mobile service data packet, only a portionof the packet may be randomized. For example, when it is assumed thatrandomizing has been performed in advance on the mobile service data bythe pre-processor 230, the data randomizer 251 may perform randomizingby removing the synchronization byte within the 4-byte MPEG header,which is included in the mobile service data packet, and by randomizingonly the remaining 3 bytes, thereby outputting the randomized data tothe RS encoder/non-systematic RS encoder 252. More specifically, themobile service data excluding the MPEG header are outputted to the RSencoder/non-systematic RS encoder 252 without being randomized. The datarandomizer 251 may perform or may not perform randomizing on known data(known data place holder) and initialization data, which are included inthe mobile service data packet.

The RS encoder/non-systematic RS encoder 252 performs an RS encodingprocess on the data being randomized by the data randomizer 251 or onthe data bypassing the data randomizer 251, so as to add 20 bytes of RSparity data. Thereafter, the processed data are outputted to the datainterleaver 253. Herein, if the inputted data correspond to the mainservice data packet, the RS encoder/non-systematic RS encoder 252performs the same systematic RS encoding process as that of theconventional broadcasting system, thereby adding the 20-byte RS paritydata at the end of the 187-byte data. Alternatively, if the inputteddata correspond to the mobile service data packet, the RSencoder/non-systematic RS encoder 252 performs a non-systematic RSencoding process. At this point, the 20-byte RS parity data obtainedfrom the non-systematic RS encoding process are inserted in apre-decided parity byte place within the mobile service data packet.

The data interleaver 253 corresponds to a byte unit convolutionalinterleaver. The output of the data interleaver 253 is inputted to theparity replacer 254 and to the non-systematic RS encoder 255.

Meanwhile, a process of initializing a memory within the trellisencoding module 256 is primarily required in order to decide the outputdata of the trellis encoding module 256, which is located after theparity replacer 254, as the known data pre-defined according to anagreement between the receiving system and the transmitting system. Morespecifically, the memory of the trellis encoding module 256 should firstbe initialized before the received known data sequence istrellis-encoded.

At this point, the beginning portion of the known data sequence that isreceived corresponds to the initialization data and not to the actualknown data. Herein, the initialization data has been included in thedata by the group formatter within the pre-processor 230 in an earlierprocess. Therefore, the process of replacing the initialization datawith memory values within the trellis encoding module 256 are requiredto be performed immediately before the inputted known data sequence istrellis-encoded.

More specifically, the initialization data are replaced with the memoryvalue within the trellis encoding module 256, thereby being inputted tothe trellis encoding module 256. At this point, the memory valuereplacing the initialization data are process with (or calculated by) anexclusive OR (XOR) operation with the respective memory value within thetrellis encoding module 256, so as to be inputted to the correspondingmemory. Therefore, the corresponding memory is initialized to ‘0’.Additionally, a process of using the memory value replacing theinitialization data to re-calculate the RS parity, so that there-calculated RS parity value can replace the RS parity being outputtedfrom the data interleaver 253, is also required.

Therefore, the non-systematic RS encoder 255 receives the mobile servicedata packet including the initialization data from the data interleaver253 and also receives the memory value from the trellis encoding module256.

Among the inputted mobile service data packet, the initialization dataare replaced with the memory value, and the RS parity data that areadded to the mobile service data packet are removed and processed withnon-systematic RS encoding. Thereafter, the new RS parity obtained byperforming the non-systematic RS encoding process is outputted to theparity replacer 255. Accordingly, the parity replacer 255 selects theoutput of the data interleaver 253 as the data within the mobile servicedata packet, and the parity replacer 255 selects the output of thenon-systematic RS encoder 255 as the RS parity. The selected data arethen outputted to the trellis encoding module 256.

Meanwhile, if the main service data packet is inputted or if the mobileservice data packet, which does not include any initialization data thatare to be replaced, is inputted, the parity replacer 254 selects thedata and RS parity that are outputted from the data interleaver 253.Then, the parity replacer 254 directly outputs the selected data to thetrellis encoding module 256 without any modification. The trellisencoding module 256 converts the byte-unit data to symbol units andperforms a 12-way interleaving process so as to trellis-encode thereceived data. Thereafter, the processed data are outputted to thesynchronization multiplexer 260.

FIG. 32 illustrates a detailed diagram of one of 12 trellis encodersincluded in the trellis encoding module 256. Herein, the trellis encoderincludes first and second multiplexers 531 and 541, first and secondexclusive OR (XOR) gates 532 and 542, and first to third memories 533,542, and 544.

More specifically, the first to third memories 533, 542, and 544 areinitialized by the memory value instead of the initialization data fromthe parity replacer 254. More specifically, when the first symbol (i.e.,two bits), which are converted from initialization data (i.e., eachtrellis initialization data byte), are inputted, the input bits of thetrellis encoder will be replaced by the memory values of the trellisencoder, as shown in FIG. 32.

Since 2 symbols (i.e., 4 bits) are required for trellis initialization,the last 2 symbols (i.e., 4 bits) from the trellis initialization bytesare not used for trellis initialization and are considered as a symbolfrom a known data byte and processed accordingly.

When the trellis encoder is in the initialization mode, the input comesfrom an internal trellis status (or state) and not from the parityreplacer 254. When the trellis encoder is in the normal mode, the inputsymbol (X2X1) provided from the parity replacer 254 will be processed.The trellis encoder provides the converted (or modified) input data fortrellis initialization to the non-systematic RS encoder 255.

More specifically, when a selection signal designates a normal mode, thefirst multiplexer 531 selects an upper bit X2 of the input symbol. And,when a selection signal designates an initialization mode, the firstmultiplexer 531 selects the output of the first memory 533 and outputsthe selected output data to the first XOR gate 532. The first XOR gate532 performs XOR operation on the output of the first multiplexer 531and the output of the first memory 533, thereby outputting the addedresult to the first memory 533 and, at the same time, as a mostsignificant (or uppermost) bit Z2. The first memory 533 delays theoutput data of the first XOR gate 532 by 1 clock, thereby outputting thedelayed data to the first multiplexer 531 and the first XOR gate 532.

Meanwhile, when a selection signal designates a normal mode, the secondmultiplexer 541 selects a lower bit X1 of the input symbol. And, when aselection signal designates an initialization mode, the secondmultiplexer 541 selects the output of the second memory 542, therebyoutputting the selected result to the second XOR gate 543 and, at thesame time, as a lower bit Z1. The second XOR gate 543 performs XORoperation on the output of the second multiplexer 541 and the output ofthe second memory 542, thereby outputting the added result to the thirdmemory 544. The third memory 544 delays the output data of the secondXOR gate 543 by 1 clock, thereby outputting the delayed data to thesecond memory 542 and, at the same time, as a least significant (orlowermost) bit Z0. The second memory 542 delays the output data of thethird memory 544 by 1 clock, thereby outputting the delayed data to thesecond XOR gate 543 and the second multiplexer 541.

The select signal designates an initialization mode during the first twosymbols that are converted from the initialization data.

For example, when the select signal designates an initialization mode,the first XOR gate 532 performs an XOR operation on the value of thefirst memory 533, which is provided through the first multiplexer 531,and on a memory value that is directly provided from the first memory533. That is, the first XOR gate 532 performs an XOR operation on 2 bitshaving the same value. Generally, when only one of the two bitsbelonging to the operand is ‘1’, the result of the XOR gate is equal to‘1’. Otherwise, the result of the XOR gate becomes equal to ‘0’.Therefore, when the value of the first memory 533 is processed with anXOR operation, the result is always equal to ‘0’. Furthermore, since theoutput of the first XOR gate 532, i.e., ‘0’, is inputted to the firstmemory 533, the first memory 533 is initialized to ‘0’.

Similarly, when the select signal designates an initialization mode, thesecond XOR gate 543 performs an XOR operation on the value of the secondmemory 542, which is provided through the second multiplexer 541, and ona memory value that is directly provided from the second memory 542.Therefore, the output of the second XOR gate 543 is also always equal to‘0’. Since the output of the second XOR gate 543, i.e., ‘0’, is inputtedto the third memory 544, the third memory 544 is also initialized to‘0’. The output of the third memory 544 is inputted to the second memory542 in the next clock, thereby initializing the second memory 542 to‘0’. In this case also, the select signal designates the initializationmode.

More specifically, when the first symbol being converted from theinitialization data byte replaces the values of the first memory 533 andthe second memory 542, thereby being inputted to the trellis encoder,each of the first and third memories 533 and 544 within the trellisencoder is initialized to ‘00’. Following the process, when the secondsymbol being converted from the initialization data byte replaces thevalues of the first memory 533 and the second memory 542, thereby beinginputted to the trellis encoder, each of the first, second, and thirdmemories 533, 542, and 544 within the trellis encoder is initialized to‘000’.

As described above, 2 symbols are required to initialize the memory ofthe trellis encoder. At this point, while the select signal designatesan initialization mode, the output bits (X2′X1′) of the first and secondmemories 533 and 542 are inputted to the non-systematic RS encoder 255,so as to perform a new RS parity calculation process.

The synchronization multiplexer 260 inserts a field synchronizationsignal and a segment synchronization signal to the data outputted fromthe trellis encoding module 256 and, then, outputs the processed data tothe pilot inserter 271 of the transmission unit 270. Herein, the datahaving a pilot inserted therein by the pilot inserter 271 are modulatedby the modulator 272 in accordance with a pre-determined modulatingmethod (e.g., a VSB method). Thereafter, the modulated data aretransmitted to each receiving system though the radio frequency (RF)up-converter 273.

Multiplexing Method of Packet Multiplexer

Data of the error correction encoded and 1/H-rate encoded primary RSframe (i.e., when the RS frame mode value is equal to ‘00’) orprimary/secondary RS frame (i.e., when the RS frame mode value is equalto ‘01’), are divided into a plurality of data groups by the groupformatter 303. Then, the divided data portions are assigned to at leastone of regions A to D of each data group or to an M/H block among theM/H blocks B1 to B10, thereby being deinterleaved. Then, thedeinterleaved data group passes through the packet formatter 305,thereby being multiplexed with the main service data by the packetmultiplexer 240 based upon a de-decided multiplexing rule. The packetmultiplexer 240 multiplexes a plurality of consecutive data groups, sothat the data groups are assigned to be spaced as far apart from oneanother as possible within the sub-frame. For example, when it isassumed that 3 data groups are assigned to a sub-frame, the data groupsare assigned to a 1^(st) slot (Slot #0), a 5^(th) slot (Slot #4), and a9^(th) slot (Slot #8) in the sub-frame, respectively.

As described-above, in the assignment of the plurality of consecutivedata groups, a plurality of parades are multiplexed and outputted so asto be spaced as far apart from one another as possible within asub-frame. For example, the method of assigning data groups and themethod of assigning parades may be identically applied to all sub-framesfor each M/H frame or differently applied to each M/H frame.

FIG. 10 illustrates an example of a plurality of data groups included ina single parade, wherein the number of data groups included in asub-frame is equal to ‘3’, and wherein the data groups are assigned toan M/H frame by the packet multiplexer 240. Referring to FIG. 10, 3 datagroups are sequentially assigned to a sub-frame at a cycle period of 4slots. Accordingly, when this process is equally performed in the 5sub-frames included in the corresponding M/H frame, 15 data groups areassigned to a single M/H frame. Herein, the 15 data groups correspond todata groups included in a parade.

When data groups of a parade are assigned as shown in FIG. 10, thepacket multiplexer 240 may either assign main service data to each datagroup, or assign data groups corresponding to different parades betweeneach data group. More specifically, the packet multiplexer 240 mayassign data groups corresponding to multiple parades to one M/H frame.Basically, the method of assigning data groups corresponding to multipleparades is very similar to the method of assigning data groupscorresponding to a single parade. In other words, the packet multiplexer240 may assign data groups included in other parades to an M/H frameaccording to a cycle period of 4 slots. At this point, data groups of adifferent parade may be sequentially assigned to the respective slots ina circular method. Herein, the data groups are assigned to slotsstarting from the ones to which data groups of the previous parade havenot yet been assigned. For example, when it is assumed that data groupscorresponding to a parade are assigned as shown in FIG. 10, data groupscorresponding to the next parade may be assigned to a sub-frame startingeither from the 12^(th) slot of a sub-frame.

FIG. 11 illustrates an example of assigning and transmitting 3 parades(Parade #0, Parade #1, and Parade #2) to an M/H frame. For example, whenthe 1^(st) parade (Parade #0) includes 3 data groups for each sub-frame,the packet multiplexer 240 may obtain the positions of each data groupswithin the sub-frames by substituting values ‘0’ to ‘2’ for i inEquation 1. More specifically, the data groups of the 1^(st) parade(Parade #0) are sequentially assigned to the 1^(st), 5^(th), and 9^(th)slots (Slot #0, Slot #4, and Slot #8) within the sub-frame. Also, whenthe 2^(nd) parade includes 2 data groups for each sub-frame, the packetmultiplexer 240 may obtain the positions of each data groups within thesub-frames by substituting values ‘3’ and ‘4’ for i in Equation 1. Morespecifically, the data groups of the 2^(nd) parade (Parade #1) aresequentially assigned to the 2^(nd) and 12^(th) slots (Slot #3 and Slot#11) within the sub-frame. Finally, when the 3^(rd) parade includes 2data groups for each sub-frame, the packet multiplexer 240 may obtainthe positions of each data groups within the sub-frames by substitutingvalues ‘5’ and ‘6’ for in Equation 1. More specifically, the data groupsof the 3rd parade (Parade #2) are sequentially assigned and outputted tothe 7^(th) and 11^(th) slots (Slot #6 and Slot #10) within thesub-frame.

As described above, the packet multiplexer 240 may multiplex and outputdata groups of multiple parades to a single M/H frame, and, in eachsub-frame, the multiplexing process of the data groups may be performedserially with a group space of 4 slots from left to right. Therefore, anumber of groups of one parade per sub-frame (NOG) may correspond to anyone integer from ‘1’ to ‘8’. Herein, since one M/H frame includes 5sub-frames, the total number of data groups within a parade that can beallocated to an M/H frame may correspond to any one multiple of ‘5’ranging from ‘5’ to ‘40’.

Processing Signaling Information

The present invention assigns signaling information areas for insertingsignaling information to some areas within each data group.

FIG. 33 illustrates an example of assigning signaling information areasfor inserting signaling information starting from the 1^(st) segment ofthe 4^(th) M/H block (B4) to a portion of the 2^(nd) segment. Morespecifically, 276(=207+69) bytes of the 4^(th) M/H block (B4) in eachdata group are assigned as the signaling information area. In otherwords, the signaling information area consists of 207 bytes of the1^(st) segment and the first 69 bytes of the 2^(nd) segment of the4^(th) M/H block (B4). For example, the 1^(st) segment of the 4^(th) M/Hblock (B4) corresponds to the 17^(th) or 173^(rd) segment of a VSBfield.

The signaling information that is to be inserted in the signalinginformation area is FEC-encoded by the signaling encoder 304, therebyinputted to the group formatter 303. The signaling information mayinclude a transmission parameter which is included in the payload regionof an OM packet, and then received to the demultiplexer 210.

The group formatter 303 inserts the signaling information, which isFEC-encoded and outputted by the signaling encoder 304, in the signalinginformation area within the data group.

Herein, the signaling information may be identified by two differenttypes of signaling channels: a transmission parameter channel (TPC) anda fast information channel (FIC).

Herein, the TPC data corresponds to signaling information includingtransmission parameters, such as RS frame information, RS encodinginformation, FIC information, data group information, SCCC information,and M/H frame information and so on. However, the TPC data presentedherein is merely exemplary. And, since the adding or deleting ofsignaling information included in the TPC may be easily adjusted andmodified by one skilled in the art, the present invention will,therefore, not be limited to the examples set forth herein.

Furthermore, the FIC data is provided to enable a fast serviceacquisition of data receivers, and the FIC data includes cross layerinformation between the physical layer and the upper layer(s).

FIG. 34 illustrates a detailed block diagram of the signaling encoder304 according to the present invention.

Referring to FIG. 34, the signaling encoder 304 includes a TPC encoder561, an FIC encoder 562, a block interleaver 563, a multiplexer 564, asignaling randomizer 565, and an iterative turbo encoder 566.

The TPC encoder 561 receives 10-bytes of TPC data and performs(18,10)-RS encoding on the 10-bytes of TPC data, thereby adding 8 bytesof parity data to the 10 bytes of TPC data. The 18 bytes of RS-encodedTPC data are outputted to the multiplexer 564.

The FIC encoder 562 receives 37-bytes of FIC data and performs(51,37)-RS encoding on the 37-bytes of FIC data, thereby adding 14 bytesof parity data to the 37 bytes of FIC data. Thereafter, the 51 bytes ofRS-encoded FIC data are inputted to the block interleaver 563, therebybeing interleaved in predetermined block units. Herein, the blockinterleaver 563 corresponds to a variable length block interleaver. Theblock interleaver 563 interleaves the FIC data within each sub-frame inTNoG(column)×51(row) block units and then outputs the interleaved datato the multiplexer 564. Herein, the TNoG corresponds to the total numberof data groups being assigned to a sub-frame. The block interleaver 563is synchronized with the first set of FIC data in each sub-frame.

The block interleaver 563 writes 51 bytes of incoming (or inputted) RScodewords in a row direction (i.e., row-by-row) and left-to-right andup-to-down directions and reads 51 bytes of RS codewords in a columndirection (i.e., column-by-column) and left-to-right and up-to-downdirections, thereby outputting the RS codewords.

The multiplexer 564 multiplexes the RS-encoded TPC data from the TPCencoder 561 and the block-interleaved FIC data from the blockinterleaver 563 along a time axis. Then, the multiplexer 564 outputs 69bytes of the multiplexed data to the signaling randomizer 565. Thesignaling randomizer 565 randomizes the multiplexed data and outputs therandomized data to the iterative turbo encoder 566.

The signaling randomizer 565 may use the same generator polynomial ofthe randomizer used for mobile service data. Also, initialization occursin each data group.

The iterative turbo encoder 566 corresponds to an inner encoderperforming iterative turbo encoding in a PCCC method on the randomizeddata (i.e., signaling information data). The iterative turbo encoder 566may include 6 even component encoders and 6 odd component encoders.

FIG. 35 illustrates an example of a syntax structure of TPC data beinginputted to the TPC encoder 561.

The TPC data are inserted in the signaling information area of each datagroup and then transmitted. The TPC data may include a sub-frame numberfield, a slot_number field, a parade_id field, a starting_group_number(SGN) field, a number_of_groups (NoG) field, a parade_repetition_cycle(PRC) field, an RS_frame_mode field, an RS_code_mode_primary field, anRS_code_mode_secondary field, an SCCC_block_mode field, anSCCC_outer_code_mode_A field, an SCCC_outer_code_mode_B field, anSCCC_outer_code_mode_C field, an SCCC_outer_code_mode_D field, anFIC_version field, a parade_continuity_counter field, and a TNoG field.

The Sub-Frame_number field corresponds to the current Sub-Frame numberwithin the M/H frame, which is transmitted for M/H framesynchronization. The value of the Sub-Frame_number field may range from0 to 4.

The Slot_number field indicates the current slot number within thesub-frame, which is transmitted for M/H frame synchronization. Also, thevalue of the Sub-Frame_number field may range from 0 to 15.

The Parade_id field identifies the parade to which this group belongs.The value of this field may be any 7-bit value. Each parade in a M/Htransmission shall have a unique Parade_id field. Communication of theParade_id between the physical layer and the management layer may beperformed by means of an Ensemble_id field formed by adding one bit tothe left of the Parade_id field. If the Ensemble_id field is used forthe primary Ensemble delivered through this parade, the added MSB shallbe equal to ‘0’. Otherwise, if the Ensemble_id field is used for thesecondary ensemble, the added MSB shall be equal to ‘1’. Assignment ofthe Parade_id field values may occur at a convenient level of thesystem, usually in the management layer.

The starting_group_number (SGN) field shall be the first Slot_number fora parade to which this group belongs, as determined by Equation 1 (i.e.,after the Slot numbers for all preceding parades have been calculated).The SGN and NoG shall be used according to Equation 1 to obtain the slotnumbers to be allocated to a parade within the sub-frame.

The number_of_Groups (NoG) field shall be the number of groups in asub-frame assigned to the parade to which this group belongs, minus 1,e.g., NoG=0 implies that one group is allocated (or assigned) to thisparade in a sub-frame. The value of NoG may range from 0 to 7. Thislimits the amount of data that a parade may take from the main (legacy)service data, and consequently the maximum data that can be carried byone parade. The slot numbers assigned to the corresponding Parade can becalculated from SGN and NoG, using Equation 1. By taking each parade insequence, the specific slots for each parade will be determined, andconsequently the SGN for each succeeding parade. For example, if for aspecific parade SGN=3 and NoG=3 (010b for 3-bit field of NoG),substituting i=3, 4, and 5 in Equation 1 provides slot numbers 12, 2,and 6.

The Parade_repetition_cycle (PRC) field corresponds to the cycle timeover which the parade is transmitted, minus 1, specified in units of M/Hframes, as described in Table 12.

TABLE 12 PRC Description 000 This parade shall be transmitted once everyM/H frame. 001 This parade shall be transmitted once every 2 M/H frames.010 This parade shall be transmitted once every 3 M/H frames. 011 Thisparade shall be transmitted once every 4 M/H frames. 100 This paradeshall be transmitted once every 5 M/H frames. 101 This parade shall betransmitted once every 6 M/H frames. 110 This parade shall betransmitted once every 7 M/H frames. 111 Reserved

For example, if PRC field value is equal to ‘001’, this indicates thatthe parade shall be transmitted once every 2 M/H frame.

The RS_Frame_mode field shall be as defined in Table 1. TheRS_Frame_mode field represents that one parade transmits one RS frame ortwo RS frames.

The RS_code_mode_primary field shall be the RS code mode for the primaryRS frame. Herein, the RS_code_mode_primary field is defined in Table 6.

The RS_code_mode_secondary field shall be the RS code mode for thesecondary RS frame. Herein, the RS_code_mode_secondary field is definedin Table 6.

The SCCC_Block_mode field represents how M/H blocks within a data groupare assigned to SCCC block. The SCCC_Block_mode field shall be asdefined in Table 7.

The SCCC_outer_code_mode_A field corresponds to the SCCC outer code modefor Region A within a data group. The SCCC outer code mode is defined inTable 8.

The SCCC_outer_code_mode_B field corresponds to the SCCC outer code modefor Region B within the data group.

The SCCC_outer_code_mode_C field corresponds be the SCCC outer code modefor Region C within the data group.

And, the SCCC_outer_code_mode_D field corresponds to the SCCC outer codemode for Region D within the data group.

The FIC_version field represents a version of FIC data.

The Parade_continuity_counter field counter may increase from 0 to 15and then repeat its cycle. This counter shall increment by 1 every(PRC+1) M/H frames. For example, as shown in Table 12, PRC=011 (decimal3) implies that Parade_continuity_counter increases every fourth M/Hframe.

The TNoG field may be identical for all sub-frames in an M/H Frame.

However, the information included in the TPC data presented herein ismerely exemplary. And, since the adding or deleting of informationincluded in the TPC may be easily adjusted and modified by one skilledin the art, the present invention will, therefore, not be limited to theexamples set forth herein.

Since the TPC data (excluding the Sub-Frame_number field and theSlot_number field) for each parade do not change their values during anM/H frame, the same information is repeatedly transmitted through allM/H groups belonging to the corresponding parade during an M/H frame.This allows very robust and reliable reception of the TPC data. Becausethe Sub-Frame_number and the Slot_number are increasing counter values,they also are robust due to the transmission of regularly expectedvalues.

Furthermore, the FIC data is provided to enable a fast serviceacquisition of data receivers, and the FIC information includes crosslayer information between the physical layer and the upper layer(s).

FIG. 36 illustrates an example of a transmission scenario of the TPCdata and the FIC data. The values of the Sub-Frame_number field,Slot_number field, Parade_id field, Parade_repetition_cycle field, andParade_continuity_counter field may corresponds to the current M/H framethroughout the 5 sub-frames within a specific M/H frame. Some of TPCparameters and FIC data are signaled in advance.

The SGN, NoG and all FEC modes may have values corresponding to thecurrent M/H frame in the first two sub-frames. The SGN, NoG and all FECmodes may have values corresponding to the frame in which the paradenext appears throughout the 3^(rd), 4^(th) and 5^(th) sub-frames of thecurrent M/H frame. This enables the M/H receivers to receive (oracquire) the transmission parameters in advance very reliably.

For example, when Parade_repetition_cycle=‘000’, the values of the3^(rd), 4^(th), and 5^(th) sub-frames of the current M/H framecorrespond to the next M/H frame. Also, whenParade_repetition_cycle=‘011’, the values of the 3^(rd), 4^(th), and5^(th) sub-frames of the current M/H frame correspond to the 4^(th) M/Hframe and beyond.

The FIC_version field and the FIC data may have values that apply to thecurrent M/H Frame during the 1^(st) sub-frame and the 2^(nd) sub-frame,and they shall have values corresponding to the M/H frame immediatelyfollowing the current M/H frame during the 3^(rd), 4^(th), and 5^(th)sub-frames of the current M/H frame.

Meanwhile, the receiving system may turn the power on only during a slotto which the data group of the designated (or desired) parade isassigned, and the receiving system may turn the power off during theremaining slots, thereby reducing power consumption of the receivingsystem. Such characteristic is particularly useful in portable or mobilereceivers, which require low power consumption. For example, it isassumed that data groups of a 1^(st) parade with NOG=3, a 2^(nd) paradewith NOG=2, and a 3^(rd) parade with NOG=3 are assigned to one M/Hframe, as shown in FIG. 37. It is also assumed that the user hasselected a mobile service included in the 1^(st) parade using the keypadprovided on the remote controller or terminal. In this case, thereceiving system turns the power on only during a slot that data groupsof the 1^(st) parade is assigned, as shown in FIG. 37, and turns thepower off during the remaining slots, thereby reducing powerconsumption, as described above. At this point, the power is required tobe turned on briefly earlier than the slot to which the actualdesignated data group is assigned (or allocated). This is to enable thetuner or demodulator to converge in advance.

Assignment of Known Data (or Training Signal)

In addition to the payload data, the M/H transmission system insertslong and regularly spaced training sequences into each group. Theregularity is an especially useful feature since it provides thegreatest possible benefit for a given number of training symbols inhigh-Doppler rate conditions. The length of the training sequences isalso chosen to allow fast acquisition of the channel during bustedpower-saving operation of the demodulator. Each group contains 6training sequences. The training sequences are specified beforetrellis-encoding. The training sequences are then trellis-encoded andthese trellis-encoded sequences also are known sequences. This isbecause the trellis encoder memories are initialized to pre-determinedvalues at the beginning of each sequence. The form of the 6 trainingsequences at the byte level (before trellis-encoding) is shown in FIG.38. This is the arrangement of the training sequence at the groupformatter 303.

The 1^(st) training sequence is located at the last 2 segments of the3^(rd) M/H block (B3). The 2^(nd) training sequence may be inserted atthe 2^(nd) and 3^(rd) segments of the 4^(th) M/H block (B4). The 2^(nd)training sequence is next to the signaling area, as shown in FIG. 5.Then, the 3^(rd) training sequence, the 4^(th) training sequence, the5^(th) training sequence, and the 6^(th) training sequence may be placedat the last 2 segments of the 4^(th), 5^(th), 6^(th), and 7^(th) M/Hblocks (B4, B5, B6, and B7), respectively.

As shown in FIG. 38, the 1^(st) training sequence, the 3^(rd) trainingsequence, the 4^(th) training sequence, the 5^(th) training sequence,and the 6^(th) training sequence are spaced 16 segments apart from oneanother. Referring to FIG. 38, the dotted area indicates trellisinitialization data bytes, the lined area indicates training data bytes,and the white area includes other bytes such as the FEC-coded M/Hservice data bytes, FEC-coded signaling data, main service data bytes,RS parity data bytes (for backwards compatibility with legacy ATSCreceivers) and/or dummy data bytes.

FIG. 39 illustrates the training sequences (at the symbol level) aftertrellis-encoding by the trellis encoder. Referring to FIG. 39, thedotted area indicates data segment sync symbols, the lined areaindicates training data symbols, and the white area includes othersymbols, such as FEC-coded mobile service data symbols, FEC-codedsignaling data, main service data symbols, RS parity data symbols (forbackwards compatibility with legacy ATSC receivers), dummy data symbols,trellis initialization data symbols, and/or the first part of thetraining sequence data symbols. Due to the intra-segment interleaving ofthe trellis encoder, various types of data symbols will be mixed in thewhite area.

After the trellis-encoding process, the last 1416 (=588+828) symbols ofthe 1^(st) training sequence, the 3^(rd) training sequence, the 4^(th)training sequence, the 5^(th) training sequence, and the 6^(th) trainingsequence commonly share the same data pattern.

Including the data segment synchronization symbols in the middle of andafter each sequence, the total length of each common training pattern is1424 symbols. The 2^(nd) training sequence has a first 528-symbolsequence and a second 528-symbol sequence that have the same datapattern. More specifically, the 528-symbol sequence is repeated afterthe 4-symbol data segment synchronization signal. At the end of eachtraining sequence, the memory contents of the twelve modified trellisencoders shall be set to zero(0).

Meanwhile, as shown in FIG. 3 and FIG. 4, one slot within the packetdomain may consist of 156 packets.

Herein, when a data group including mobile service data is transmittingduring one slot, one data group is transmitted through the first 118packets within the slot, and main service data are transmitted throughthe remaining 38 packets. More specifically, main service data of atleast 4.72 Mbps are transmitted through 38 packets within one slot. Inother words, approximately 24.4% (=38/(118+38)*100) of main service dataare transmitted through 38 packets within one slot.

Accordingly, the present invention proposes a method that canefficiently transmit a larger amount of mobile service data by reducingthe limitation level of 4.72 Mbps (or 24.4%).

More specifically, when mobile service data exist in consecutive slots,38 packets, which are allocated for the main service data, may existbetween the two data groups within the packet domain (i.e., prior tobeing interleaved). More specifically, when two data groups are assigned(or positioned) to a neighboring slot, 38 packets for the main servicedata may exist between one set of 118 packets corresponding to theprevious data group and another set of 118 packets corresponding to thenext data group.

According to an exemplary embodiment of the present invention, at leasta portion of the 38 packets may be used in order to additionallytransmit mobile service data.

FIG. 40 (a) shows an exemplary data group structure prior tointerleaving, i.e., when mobile service data exist in consecutive slotswithin a packet domain, and FIG. 40 (b) shows an exemplary data groupstructure after interleaving, i.e., when mobile service data exist inconsecutive slots within a segment domain.

More specifically, in order to have regions C/D within the data groupafter the interleaving process positioned (or assigned) as shown in FIG.40( b), regions C/D within the data group prior to the interleavingprocess are positioned (or assigned) as shown in FIG. 40( a).

In the description of the present invention, the 38 packets, which wereallocated for the initial main service data within the packet domain,will be referred to as a bonding region for simplicity.

Also, according to the present invention, the bonding region may furtherinclude regions C/D. For example, in a packet domain, as shown in FIG.40( a), in data packets having data bytes corresponding to regions A/Band data bytes corresponding to regions C/D co-existing therein, amongthe 118 packets, the bonding region includes byte positionscorresponding to regions C/D and 38 packet positions (or places) thatwere used for the initial main service data. Additionally, wheninterleaving is performed on the data of the two slots including thebonding region, as shown in FIG. 40( a), the bonding region isconfigured within the segment domain, as shown in FIG. 40( b).

More specifically, within the segment domain, the bonding regionincludes 60 segments comprising segments that were used for transmittingthe initial main service data and segments that were used fortransmitting regions C/D. Also, the bonding region further includessymbol positions of regions C/D belonging to segments having symbols ofregions A/B and symbols of regions C/D co-exist therein. In other words,in the segment domain, the bonding region includes a region, which wasallocated for the main service data positioned between two contiguousdata groups, a portion of region B, and regions C/D. In the segmentdomain, the region that was allocated for the main service datacorresponds to a region that was created by a dispersion (or scattering)of main service data within the 38 packets existing in a single slotsection within the packet domain, after the data interleaving process.

According to an exemplary embodiment of the present invention, basedupon the packet domain shown in FIG. 40 (a) (i.e., prior tointerleaving), the bonding region according to the present inventionincludes a whole set of 38 packets located between two data groups, aportion of 36 packets belonging to a previous data group of the two datagroups, and a portion of 37 packets belonging to a next (or subsequent)data group.

According to the exemplary embodiment of the present invention, basedupon the segment domain shown in FIG. 40 (b) (i.e., after interleaving),the bonding region according to the present invention includes a wholeset of 60 segments located between two data groups, a portion of 15segments of region B belonging to a previous data group of the two datagroups, and a portion of 14 segments of region B belonging to a next (orsubsequent) data group.

In the description of the present invention, mobile service data beingallocated to regions A/B within the data group will hereinafter bereferred to first mobile service data, and mobile service data beingallocated to the bonding region will hereinafter be referred to secondmobile service data, for simplicity. The second mobile service data mayalso be referred to as Extended mobile service data or additional mobileservice data.

The present invention may allocate (or insert) the second mobile servicedata to (or in) the bonding region and transmit the processed data, orthe present invention may allocate (or insert) and transmit the secondmobile service data along with the main service data. Moreover, thepresent invention may also allocate (or insert) and transmit only themain service data. Just as the first mobile service data, the secondmobile service data are allocated to the bonding region, after beingprocessed with RS frame encoding and turbo encoding procedures in theblock processor 302.

According to an exemplary embodiment of the present invention, in caseof allocating second mobile service data to the bonding region andtransmitting the processed data, in order to enhance the receivingperformance, multiple known data sequences, which are known based uponan agreement between the transmitting system and the receiving system,may be additionally allocated to (or inserted in) predeterminedpositions (or places), thereby being transmitted. Herein, each knowndata sequence may correspond to a short known data sequence or maycorrespond to a long known data sequence.

Meanwhile, if new known data are inserted to the bonding region, and ifthe positions of the second mobile service data or the RS parity dataare changed to a different data group format other than the data groupformat shown in FIG. 5, a receiver that can receive and process datagroups shown in FIG. 5 cannot receive the newly changed data group. Inthe present invention, it is assumed that the first mobile service data,which are positioned in the data group shown in FIG. 5, are encoded in apre-arranged encoding order by the pre-processor of the transmitter.Accordingly, the receiver performs decoding based upon this assumption.However, if the pre-arranged agreement is changed (or modified), asshown in FIG. 40( b), the receiver is incapable of performing decoding.

For example, when data of a primary RS frame are inserted in regionsA/B/C/D within a data group, and when the RS frame mode value is set to‘00’, a receiver that can receive a data group shown in FIG. 5 isincapable of decoding the primary RS frame. In another example, it isassumed that the data of the primary RS frame are transmitted throughregions A/B within the data group, and that data of the secondary RSframe are transmitted through the bonding region including regions C/Dwithin the data group. In this case, the RS frame mode value is set to‘01’, and the receiver that can receive and process data groups shown inFIG. 5 is capable of decoding the primary RS frame but incapable ofdecoding the secondary RS frame. This is because regions A/B have thesame data group format as the group shown in FIG. 5 and also because thebonding region including regions C/D does not have the same data groupformat as the group shown in FIG. 5.

Therefore, according to an embodiment of the present invention, theprimary RS frame is transmitted through regions A/B. Additionally,according to the embodiment of the present invention, the RS frame modevalue is set to ‘01’, and the SCCC block mode value is set to ‘00’. Thisindicates that the data of the primary RS frame are inserted to regionsA/B of regions A/B/C/D within the data group and, also, that the SCCCblock is configured of a single M/H block. As described above, when theRS frame mode value is equal to ‘00’, this indicates that the data ofthe primary RS frame are inserted to regions A/B/C/D within the datagroup and then transmitted. And, when the RS frame mode value is equalto ‘01’, this indicates that the data of the primary RS frame areinserted to regions A/B within the data group and then transmitted. Inthis case, a receiver, which can receive and process a data group shownin FIG. 5, may be capable of receiving the primary RS frame that istransmitted through regions A/B without any difficulty. Also, accordingto the embodiment of the present invention, the present inventiontransmits the secondary RS frame through the bonding region. In thiscase, the first mobile service data are included in the primary RSframe, and the second mobile service data are included in the secondaryRS frame.

According to the embodiment of the present invention, the second mobileservice data may be allocated to (or inserted in) a portion (between1˜38 packets) of the bonding region and then transmitted, and the mainservice data may be allocated to (or inserted in) another portion of thebonding region and then transmitted. In another example, only the secondmobile service data may be allocated to the bonding region and thentransmitted, without allocating the main service data.

At this point, the group formatter 303 may allocate the second mobileservice data and the main service data (or main service data placeholders) to the bonding region by using various methods.

FIG. 41( a) and FIG. 41( b) show an example of the second mobile servicedata and main service data being allocated to the bonding region in thepacket domain (i.e., prior to interleaving). FIG. 42 shows an example ofthe second mobile service data and main service data being allocated tothe bonding region in the segment domain (i.e., after interleaving).More specifically, in the packet domain, the second mobile service dataand the main service data are allocated, so as to be positioned as shownin FIG. 41( a) and FIG. 41( b). And, in the segment domain, the secondmobile service data and the main service data (or main service dataplace holders) are allocated, so as to be positioned as shown in FIG.42.

The packet domain will be given as an example for the followingdescription. Herein, among the 38 packets, the second mobile servicedata may be allocated to odd-numbered packets, and the main service datamay be allocated to even-numbered packets. In another example, among the38 packets, the second mobile service data may be allocated toodd-numbered 2-packet sets, and the main service data may be allocatedto even-numbered 2-packet sets. In yet another example, among the 38packets, the second mobile service data may be allocated to the first 19packets, and the main service data may be allocated to the next (orremaining) 19 packets. In yet another example, the second mobile servicedata may be allocated to all 38 packets.

The rule for allocating the second mobile service data and/or the mainservice data may be easily changed or altered by anyone skilled in theart. Therefore, the present invention will not be limited only to theallocation examples given herein.

According to another exemplary embodiment of the present invention, inaddition to the region corresponding to the 38 packets within bondingregion, the second mobile service data and known data may also bepositioned in (or assigned to) regions C/D.

At this point, according to the embodiment of the present invention, aPID or null packet PID, which is not used in a main service, isallocated to an MPEG header of a packet within the bonding region, towhich the second mobile service data are allocated. Accordingly, theconventional receiver may be capable of discarding (or removing) thesecond mobile service data packet without having to process thecorresponding data packet.

More specifically, FIG. 41( a) and FIG. 41( b) show an exemplary dataalignment within the bonding region prior to interleaving, and FIG. 42shows an exemplary data alignment within the bonding region afterinterleaving.

As shown in FIG. 41 and FIG. 42, if the main service data are allocatedto a portion of the bonding region, audio/video jitter of the mainservice data, which may occur due to a continuous transmission of thesecond mobile service data, no longer increases. More specifically, dueto the insertion of the second mobile service data, the main servicedata may also be transmitted via burst transmission. At this point, inorder to receive the main services, the receiver should buffer the mainservice data, e.g., audio/video data in advance. However, as thecontinuous transmission time of the second mobile service data becomeslonger, and as the transmission frequency of the main service datadecreases accordingly, the required buffer size increases.

If the second mobile service data are allocated to all 38 packets of thebonding region and then transmitted, the main service data cannot betransmitted for a period of at least 274 packets (=118+38+118). Thus,audio/video jitter may occur due to a buffer overflow, which is causedby such failure to transmit main service data. According to theembodiment of the present invention, transmission rate of the mainservice data is decided based upon a number of packets, among the 38packets of the bonding region, having the main service data allocatedthereto and a number of data groups being bonded.

Meanwhile, referring to the data structure after interleaving, as shownin FIG. 42, the main service data bytes are vertically aligned in thebonding region. In this case, it is impossible to insert long known datasequences in the bonding region.

Therefore, according to the embodiment of the present invention, whenthe main service data bytes are vertically aligned in the bondingregion, as shown in FIG. 42, the known data bytes are uniformly insertedas shown in FIG. 43.

FIG. 43 illustrates an example of uniformly inserting known data bytesin a bonding region within a segment domain shown in FIG. 42. Herein,known data are inserted in the bonding region in order to acquire knowndata symbols, which are pre-decided based upon an agreement between thetransmitting system and the receiving system, after a trellis (TCM)encoding process. Therefore, in this case also, initialization data(i.e., trellis initialization bytes) of the trellis encoder arerequired. The initialization data are used for initializing a memorywithin the trellis encoder and are not transmitted to the receiver.

At this point, the transmitter is provided with 12 trellis encoders,and, since each data byte is inputted to each trellis encoder, by usingthe bytes corresponding to each specific trellis encoder as the knowndata bytes, the number of trellis initialization bytes may be largelyreduced. Herein, since the trellis initialization bytes require parityreplacement, the number of positions (or places) of the trellisinitialization bytes are limited in accordance with the positions (orplaces) of systematic/non-systematic RS parity bytes included in thecorresponding packet. According to the embodiment of the presentinvention, based upon a data structure after the interleaving process,the trellis initialization bytes are outputted earlier than the RSparity bytes. Furthermore, the known data bytes may be used forenhancing the performance of receiving the second mobile service data aswell as receiving the main service data.

FIG. 44 illustrates an exemplary data structure after interleaving(i.e., prior to deinterleaving), wherein the main service data are notinserted and only the second mobile service data are inserted in thebonding region, and wherein short known data sequences are uniformlyinserted in-between the second mobile service data.

FIG. 45 illustrates an exemplary data structure after interleaving(i.e., prior to deinterleaving), wherein the main service data are notinserted and only the second mobile service data are inserted in thebonding region, and wherein long known data sequences are insertedin-between the second mobile service data at consistent segmentintervals. Most particularly, FIG. 45 shows an exemplary embodimentwherein 4 long known data sequences are inserted in the bonding region.According to the embodiment of the present invention, referring to the60 segments within the bonding region, which is positioned between twocontiguous data groups, the 4 long known data sequences are respectivelyinserted in segment 7, segment 23, segment 35, and segment 51. Herein,according to the embodiment of the present invention, the trellisinitialization bytes are inserted before each known data sequence. Thetrellis initialization bytes are used for initializing the memory of thetrellis encoder and are not transmitted to the receiving system.

If the second mobile service data are transmitted through all slots, soas to bond each of the data groups to one another, and if all secondmobile service data are allocated to the bonding region, thiscorresponds to a full channel mobile service. In this case, backwardcompatibility with the conventional 8VSB is no longer significant.Accordingly, MPEG headers having a PID, which is not used in the mainservice, or MPEG headers having a null packet PID, orsystematic/non-systematic RS parity data for main services are also nolonger significant. Therefore, in this case, the second mobile servicedata may be inserted in the RS parity places and MPEG header places thatwere used for the main services within the bonding region, thereby beingtransmitted. Thus, the transmission rate of the second mobile servicedata may be more increased. Furthermore, the trellis initializationbytes, which were used due to the RS parity and MPEG header for the mainservices, may be used as the known data. However, in this case also,according to the embodiment of the present invention, in order to allowthe conventional receiver to perform smooth data reception, the primaryRS frame region is maintained without any modification.

Meanwhile, according to the present invention, if consecutive datagroups are bonded, a head region and a tail region of the correspondingdata groups may be categorized into 3 different data group types, asshown in FIG. 46( a) to FIG. 46( c). In the description of the presentinvention, based upon the data structure after interleaving, a regionincluding the whole M/H blocks B1, B2 of the data group and a portion ofM/H blocks B3, B3 will be referred to as the head region, and a regionincluding the whole M/H blocks B9, B10 of the data group and a portionof M/H block B8 will be referred to as the tail region, for simplicity.Furthermore, a region excluding the head region and the tail region willbe referred to as a body region, for simplicity. Herein, the regionincluding the whole M/H blocks B1, B2, a portion of M/H block B3, thewhole M/H blocks B9, B10, and a portion of M/H block B8 of the datagroup correspond to regions C/D of the data group prior to interleaving.

More specifically, according to the present invention, when consecutivedata groups are being bonded, only the head region of the data group maybe included in the bonding region, as shown in FIG. 46( a), or only thetail region of the data group may be included in the bonding region, asshown in FIG. 46( b), or both the head region and the tail region of thedata group may be included in the bonding region, as shown in FIG. 46(c). Hereinafter, in the description of the present invention, the casewhere the head region of the data group is included in the bondingregion, as shown in FIG. 46( a), will be referred to as head bonding,the case where the tail region of the data group is included in thebonding region, as shown in FIG. 46( b), will be referred to as tailbonding, and the case where both the head region and the tail region ofthe data group are included in the bonding region, as shown in FIG. 46(c), will be referred to as head-tail bonding, for simplicity.Furthermore, hereinafter, the data group shown in FIG. 5 will bereferred to as a normal (or general) data group (or first data group),and the data group including the bonding region will be referred to as abonding data group (or second data group), for simplicity.

According to the present invention, as shown in FIG. 43 and FIG. 44,multiple short known data sequences may be inserted in the bondingregion, and, as shown in FIG. 45, multiple long known data sequences maybe inserted in the bonding region. Also, when it is assumed that themain service data are not allocated to the bonding region, in case of atail bonding, the main service data may severely interfere with the M/Hblocks B1, B2, and, in case of a head bonding, the main service data mayseverely interfere with the M/H blocks B9, B10. In this case, thereceiving performance (i.e., SCCC decoding performance) of the M/Hblocks B1, B2 or the M/H blocks B9, B10 is degraded. Additionally, sincethe number of the second mobile service data bytes, which are allocatedto the M/H blocks B1, B2 or the M/H blocks B9, B10, is small, the SCCCblock length is also short, accordingly. This also acts as a factor ofdegrading the receiving performance of the M/H blocks B1, B2 or the M/Hblocks B9, B10. Conversely, since the main service data do not interferewith the M/H blocks, the receiving performance of the second mobileservice data of the bonding region is excellent.

Therefore, according to the embodiment of the present invention, inorder to enhance the receiving performance, the block processor 302 ofthe present invention combines the second mobile service data of thebonding region with the first mobile service data of a non-bondingregion, so as to configure an SCCC block. Then, the block processor 302performs SCCC encoding (i.e., 1/H-rate encoding) in SCCC block units.For example, in case of the tail bonding, the first mobile service dataof the head region and the second mobile service data of the tail regionare collectively SCCC-encoded by the block processor 302, so that theSCCC-encoded mobile service data of the head region and the tail regioncan be evenly distributed (or dispersed) and assigned to mobile servicedata symbol places of the head and tail regions, thereby beingtransmitted. Accordingly, any encoding data error of the head regionthat may occur in a transmission channel may be SCCC decoded by usingthe encoding data of the tail region having excellent receivingperformance. Therefore, the receiving performance of the first mobileservice data included in the head region may be enhanced.

According to an exemplary embodiment of the present invention, in orderto enhance the receiving performance, the block processor 302 maycombine two M/H blocks so as to create one SCCC block, therebyperforming SCCC encoding (i.e., 1/H-rate encoding) in SCCC block units.For example, in case of the head bonding or the tail bonding, M/H blockB1 and M/H block B9 are combined to configure one SCCC block, therebybeing processed with 1/H-rate encoding, and M/H block B2 and M/H blockB10 are combined to configure one SCCC block, thereby being processedwith 1/H-rate encoding. Accordingly, the receiving performance of M/Hblocks B1, B2 or M/H blocks B9, B10, which tend to be degraded in areception environment undergoing frequent (or severe) channel changes,may be supplemented.

According to another exemplary embodiment of the present invention, inorder to enhance the receiving performance, the bonding region isdivided into a plurality of M/H blocks. Then, a divided M/H block of thebonding region are combined with an M/H block of the non-bonding regionso as to configure an SCCC block. Thereafter, SCCC encoding (i.e.,1/H-rate encoding) is performed in SCCC block units. According to theembodiment of the present invention, the bonding region is divided into4 extended M/H blocks EB1-EB4. At this point, among the 4 extended M/Hblocks, the first 2 extended M/H blocks EB1, EB2 are each combined withthe 2 M/H blocks of the head region corresponding to the first datagroup of the two consecutive data groups (i.e., the non-bonding region).And, among the 4 extended M/H blocks, the remaining 2 extended M/Hblocks EB3, EB4 are each combined with the 2 M/H blocks of the tailregion corresponding to the next (or second) data group of the twoconsecutive data groups (i.e., the non-bonding region). According to theembodiment of the present invention, one SCCC block is configured bycombining 2 M/H blocks of the bonding region with 2 M/H blocks of thenon-bonding region. Thereafter, SCCC encoding (i.e., 1/H-rate encoding)may be performed in SCCC block units. According to another exemplaryembodiment of the present invention, one SCCC block is configured bycombining 1 M/H block of the bonding region with 1 M/H block of thenon-bonding region. Thereafter, SCCC encoding (i.e., 1/H-rate encoding)may be performed in SCCC block units. As described above, when the SCCCencoding is performed by the block processor 302, information related toSCCC shall be transmitted to the receiving system in order to accuratelyrecover the first and second mobile service data. According to anembodiment of the present invention, the SCCC related information may beincluded in signaling information, e.g., TPC, and then transmitted.

Hereinafter, a rule for allocating a general data group and a bondingdata group will be described in detail. Basically, according to theembodiment of the present invention, the M/H frame structure, thesubframe structure, and the rule for allocating a data group to a slotbelonging to a subframe may be identical to the above-described rule forallocating only the data group of FIG. 5. Also, data groups configuringonly one parade may be configured of only one of the bonding data groupand the general data group. In the conventional M/H system, which canprocess only the data groups of FIG. 5, data groups configuring a singleparade share the same FEC mode (SCCC block mode, RS frame mode).Accordingly, in order to maintain such compatibility with theconventional M/H system, each of the data groups configuring thecorresponding parade shall be defined to have the same format. Also, inorder to assign (or position) the bonding data group to a slotneighboring (or adjacent to) the general data group, a bonding regionshould not exist between the two data groups. In other words, when thebonding data group is assigned to the first slot, and when the generaldata group is assigned to the second slot, among the 3 different bondingdata group types, it will be impossible to perform tail bonding and headbonding. This is because the tail region of the bonding data groupoverlaps with the head region of the general data group. Also, accordingto an embodiment of the present invention, among the 3 differentcombination types, one combination type will be identically applied tothe bonding data groups configuring one parade, in accordance with thecombination with other data groups within a slot. According to theembodiment of the present invention, this information will be notifiedto the receiver by using signaling information (e.g., TPC data).

Furthermore, if all data groups within a subframe correspond to thebonding data groups, a maximum of 16 bonding data groups may beallocated. More specifically, the maximum TNoG(=TNoG_BG) value may beequal to 16. However, when both the bonding data groups and the generaldata groups are assigned to a subframe, there may be limitations in theallocation of data groups due to the above-described overlapping of thehead region and the tail region.

FIG. 47( a) to FIG. 47( c) respectively illustrate exemplary rules forallocating general data groups and bonding data groups to a singlesubframe. TNoG_NG corresponds to a total number of general data groupsbeing allocated to a single subframe, and TNoG_BG corresponds to a totalnumber of bonding data groups being allocated to a single subframe.Herein, the total number of data groups being allocated to a singlesubframe (TNoG) should be equal to TNoG_NG+TNoG_BG=16.

FIG. 47( a) corresponds to when TNoG_NG≧4 and when TNoG_BG=8. Mostparticularly, FIG. 47( a) corresponds to when TNoG_NG=8 and whenTNoG_BG=8. In FIG. 47( a), one general data group is first assigned,and, subsequently, 2 bonding data groups and 2 general data groups arealternately assigned, and then a general data group is assigned to thelast slot (Slot #15). According to another embodiment of the presentinvention, the general data groups are first divided into a first setincluding 4 general data groups and a second set including the remaining(TNoG_NG−4) number of general data groups. Then, the set of 4 generaldata groups is first assigned, and 8 bonding data groups are assignedafterwards. Finally, the second set of general data groups (TNoG_NG−4number of general data groups) may be assigned. Therefore, in case ofFIG. 47( a), a maximum of 87.8% (=100−(24.4*8/16)) of the mobile servicedata may be transmitted. More specifically, since the occupation rate ofthe main service data is equal to 12.2%, a TS packet transmission rateof the main service data may be calculated as 19.39*0.122=2.36 Mbps.

FIG. 47( b) corresponds to when TNoG_NG≦4, and whenTNoG_BG=12+(4−TNoG_NG). Most particularly, FIG. 47( b) corresponds towhen TNoG_NG=4, and when TNoG_BG=12. In FIG. 47( b), 3 bonding datagroups and 1 general data group are alternately assigned. According toanother embodiment of the present invention, the bonding data groups maybe first assigned, and the general data group may be assigned to theremaining position (or place). In case of FIG. 47( b), a maximum of93.9% (=100−(24.4*4/16)) of the mobile service data may be transmitted.More specifically, since the occupation rate of the main service data isequal to 6.1%, a TS packet transmission rate of the main service datamay be calculated as 19.39*0.061=1.12 Mbps.

FIG. 47( c) corresponds to when TNoG_NG=0, and when TNoG_BG=16. In thiscase, a maximum of 100% of the mobile service data may be transmitted.

According to the present invention, indication information identifying aparade configured of a bonding data group and a parade configured of ageneral data group, information indicating a bonding data group type(e.g., any one of head bonding, tail bonding, and head-tail bonding),which is used in the corresponding parade, TNoG_NG, TNoG_BG, a rule forallocating the general data group and the bonding data group, and so onmay be included in the signaling information, e.g., TPC, and thentransmitted to the receiver. Thereafter, the receiver receives suchsignaling information and performs demodulation, equalization, anddecoding on the bonding data group.

Furthermore, with the exception for second mobile service data, mainservice data, and known data, reference may be made to theabove-described FIG. 1 to FIG. 39 for the remaining data. Therefore,detailed description of the same will be omitted for simplicity.

Receiving System

FIG. 48 is a block diagram illustrating a receiving system according toan embodiment of the present invention.

The receiving system of FIG. 48 includes a tuner 1301, a demodulatingunit 1302, a demultiplexer 1303, a program table buffer 1304, a programtable decoder 1305, a program table storage unit 1306, a data handler1307, a middleware engine 1308, an A/V decoder 1309, an A/Vpost-processor 1310, an application manager 1311, and a user interface1314. The application manager 1311 may include a channel manager 1312and a service manager 1313.

In FIG. 48, solid lines indicate data flows and dotted lines indicatecontrol flows.

The tuner 1301 tunes to a frequency of a specific channel through any ofan antenna, a cable, or a satellite and down-converts the frequency toan Intermediate Frequency (IF) signal and outputs the IF signal to thedemodulating unit 1302.

Herein, the tuner 1301 is controlled by the channel manager 1312 in theapplication manager 1311 and reports the result and strength of abroadcast signal of the tuned channel to the channel manager 1312. Datareceived through the frequency of the specific channel includes mainservice data, first mobile service data, second mobile service data, atransmission parameter, and program table information for decoding themain service data and the first mobile service data and the secondmobile service data.

The demodulating unit 1302 performs VSB demodulation, channelequalization, etc., on the signal output from the tuner 1301 andidentifies and separately outputs main service data and the first mobileservice data and the second mobile service data. The demodulating unit1302 will be described in detail in a later.

On the other hand, the transmitter can transmit signaling information(or TPC information) including transmission parameters by inserting thesignaling information into at least one of a field synchronizationregion, a known data region, and a mobile service data region.Accordingly, the demodulating unit 1302 can extract the transmissionparameters from the field synchronization region, the known data region,and the mobile service data region.

The transmission parameters may include M/H frame information, sub-frameinformation, slot information, parade-related information (for example,a parade id, a parade repeat period, etc.), information of data groupsin a sub-frame, RS frame mode information, RS code mode information,SCCC block mode information, SCCC outer code mode information, FICversion information, etc. The transmission parameter may further includebonding region information, indication information identifying a paradeconfigured of a bonding data group and a parade configured of a generaldata group, information indicating a bonding data group type, which isused in the corresponding parade, TNoG_NG, TNoG_BG, a rule forallocating the general data group and the bonding data group, and so on.In the present invention, the data group may correspond to at least oneof a general data group and a bonding data group. Also, the mobileservice data may correspond to at least one of first mobile service dataand second mobile service data.

The demodulating unit 1302 performs block decoding, RS frame decoding,etc., using the extracted transmission parameters. For example, thedemodulating unit 1302 performs block decoding of each region in a datagroup with reference to SCCC-related information (for example, SCCCblock mode information or an SCCC outer code mode) included in thetransmission parameters and performs RS frame decoding of each regionincluded in the data group with reference to RS-related information (forexample, an RS code mode).

In the embodiment of the present invention, an RS frame including mobileservice data demodulated by the demodulating unit 1302 is input to thedemultiplexer 1303.

That is, data inputted to the demultiplexer 1303 has an RS frame payloadformat as shown in FIG. 17( a) or FIG. 17( b). More specifically, the RSframe decoder of the demodulating unit 1302 performs the reverse of theencoding process performed at the RS frame encoder of the transmissionsystem to correct errors in the RS frame and then outputs theerror-corrected RS frame payload to a data derandomizer. The dataderandomizer then performs derandomizing on the error-corrected RS framepayload through the reverse of the randomizing process performed at thetransmission system to obtain a primary RS frame payload as shown inFIG. 17( a) or a secondary RS frame payload as shown in FIG. 17( b).

The demultiplexer 1303 may receive RS frame payloads of all parades andmay also receive only an RS frame payload of a parade including a mobileservice that the user desires to receive through power supply control.For example, when RS frame payloads of all parades are received, thedemultiplexer 1303 can demultiplex a parade including a mobile servicethat the user desires to receive using a parade_id.

Because one or two RS frames are transmitted through one parade and oneensemble is mapped into one RS frame, when one parade carries two RSframes, the demultiplexer 1303 needs to identify an RS frame carrying anensemble including mobile service data to be decoded from a paradecontaining a mobile service that the user desires to receive. That is,when a received single parade or a parade demultiplexed from a pluralityof parades carries a primary ensemble and a secondary ensemble, thedemultiplexer 1303 selects one of the primary and secondary ensembles.

In an embodiment, the demultiplexer 1303 can demultiplex an RS framecarrying an ensemble including mobile service data to be decoded usingan ensemble_id created by adding one bit to a left position of theparade_id.

The demultiplexer 1303 refers to the M/H header of the M/H service datapacket within the RS frame payload belonging to the ensemble includingthe mobile service data that are to be decoded, thereby identifying whenthe corresponding M/H service data packet is the signaling tableinformation or the IP datagram of the mobile service data.Alternatively, when the signaling table information and the mobileservice data are both configured in the form of IP datagrams, thedemultiplexer 1303 may use the IP address in order to identify the IPdatagram of the program table information and the mobile service data.

Herein, the identified signaling table information is outputted to theprogram table buffer 1304. And, audio/video/data streams are separatedfrom the IP datagram of mobile service data that are to be selectedamong the IP datagrams of the identified mobile service data, therebybeing respectively outputted to the A/V decoder 1309 and/or the datahandler 1307.

According to an embodiment of the present invention, when thestuff_indicator field within the M/H header of the M/H service datapacket indicates that stuffing bytes are inserted in the payload of thecorresponding M/H service data packet, the demultiplexer 1303 removesthe stuffing bytes from the payload of the corresponding M/H servicedata packet. Then, the demultiplexer 1303 identifies the program tableinformation and the mobile service data. Thereafter, the demultiplexer1303 identifies A/V/D streams from the identified mobile service data.

The program table buffer 1304 temporarily stores the section-typeprogram table information and then outputs the section-type programtable information to the program table decoder 1305.

The program table decoder 1305 identifies tables using a table_id and asection_length in the program table information and parses sections ofthe identified tables and produces and stores a database of the parsedresults in the program table storage unit 1306. For example, the programtable decoder 1305 collects sections having the same table identifier(table_id) to construct a table. The program table decoder 1305 thenparses the table and produces and stores a database of the parsedresults in the program table storage unit 1306.

The A/V decoder 1309 decodes the audio and video streams outputted fromthe demultiplexer 1303 using audio and video decoding algorithms,respectively. The decoded audio and video data is outputted to the A/Vpost-processor 1310.

Here, at least one of an AC-3 decoding algorithm, an MPEG audio decodingalgorithm, an MPEG 4 audio decoding algorithm, an AAC decodingalgorithm, an AAC+ decoding algorithm, an HE AAC decoding algorithm, anAAC SBR decoding algorithm, an MPEG surround decoding algorithm, and aBSAC decoding algorithm can be used as the audio decoding algorithm andat least one of an MPEG 2 video decoding algorithm, an MPEG 4 videodecoding algorithm, an H.264 decoding algorithm, an SVC decodingalgorithm, and a VC-1 decoding algorithm can be used as the audiodecoding algorithm.

The data handler 8507 processes data stream packets required for databroadcasting among data stream packets separated (or identified) by thedemultiplexer 1303 and provides the processed data stream packets to themiddleware engine 1310 to allow the middleware engine 1310 to bemultiplexed them with A/V data. In an embodiment, the middleware engine1310 is a Java middleware engine.

The application manager 1311 receives a key input from the TV viewer anddisplays a Graphical User Interface (GUI) on the TV screen in responseto a viewer request through a User Interface (UI). The applicationmanager 1311 also writes and reads information regarding overall GUIcontrol of the TV, user requests, and TV system states to and from amemory (for example, NVRAM or flash memory). In addition, theapplication manager 1311 can receive parade-related information (forexample, a parade_id) from the demodulating unit 1302 to control thedemultiplexer 1303 to select an RS frame of a parade including arequired mobile service. The application manager 1311 can also receivean ensemble_id to control the demultiplexer 1303 to select an RS frameof an ensemble including mobile service data to be decoded from theparade. The application manager 1311 also controls the channel manager1312 to perform channel-related operations (for example, channel mapmanagement and program table decoder operations).

The channel manager 1312 manages physical and logical channel maps andcontrols the tuner 1301 and the program table decoder 1305 to respond toa channel-related request of the viewer. The channel manager alsorequests that the program table decoder 1305 parse a channel-relatedtable of a channel to be tuned and receives the parsing results from theprogram table decoder 1305.

Demodulating unit within Receiving system

FIG. 49 illustrates an example of a demodulating unit in a digitalbroadcast receiving system according to the present invention. Thedemodulating unit of FIG. 49 uses known data information, which isinserted in the mobile service data section and, then, transmitted bythe transmitting system, so as to perform carrier synchronizationrecovery, frame synchronization recovery, and channel equalization,thereby enhancing the receiving performance. Also the demodulating unitmay turn the power on only during a slot to which the data group of thedesignated (or desired) parade is assigned, thereby reducing powerconsumption of the receiving system.

Referring to FIG. 49, the demodulating unit includes an operationcontroller 2000, a demodulator 2002, an equalizer 2003, a known sequencedetector 2004, a block decoder 2005, and a RS frame decoder 2006. Thedemodulating unit may further include a main service data processor2008. The main service data processor 2008 may include a datadeinterleaver, a RS decoder, and a data derandomizer. The demodulatingunit may further include a signaling decoder 2013. The receiving systemalso may further include a power controller 5000 for controlling powersupply of the demodulating unit.

More specifically, a frequency of a particular channel tuned by a tunerdown converts to an intermediate frequency (IF) signal. Then, thedown-converted data 2001 outputs the down-converted IF signal to thedemodulator 2002 and the known sequence detector 2004. At this point,the down-converted data 2001 is inputted to the demodulator 2002 and theknown sequence detector 2004 via analog/digital converter ADC (notshown). The ADC converts pass-band analog IF signal into pass-banddigital IF signal.

The demodulator 2002 performs self gain control, carrier recovery, andtiming recovery processes on the inputted pass-band digital IF signal,thereby modifying the IF signal to a base-band signal. Then, thedemodulator 2002 outputs the newly created base-band signal to theequalizer 2003 and the known sequence detector 2004.

The equalizer 2003 compensates the distortion of the channel included inthe demodulated signal and then outputs the channel distortioncompensated signal to the block decoder 2005 and the signaling decoder2013.

At this point, the known sequence detector 2004 detects the knownsequence position information inserted by the transmitting end from theinput/output data of the demodulator 2002 (i.e., the data prior to thedemodulation process or the data after the demodulation process).Thereafter, the position information along with the symbol sequence ofthe known data, which are generated from the detected position, isoutputted to the operation controller 2000, the demodulator 2002, theequalizer 2003, and the signaling decoder 2013. Also, the known sequencedetector 2004 outputs a set of information to the block decoder 2005.This set of information is used to allow the block decoder 2005 of thereceiving system to identify the mobile service data that are processedwith additional encoding from the transmitting system and the mainservice data that are not processed with additional encoding.

In addition, although the connection status is not shown in FIG. 49, theinformation detected from the known sequence detector 2004 may be usedthroughout the entire receiving system and may also be used in the RSframe decoder 2006.

The data demodulated in the demodulator 2002 or the data equalized inthe channel equalizer 2003 is inputted to the signaling decoder 2013.The known data position information detected in the known sequencedetector 2004 is inputted to the signaling decoder 2013.

The signaling decoder 2013 extracts and decodes signaling information(e.g., TPC information), which inserted and transmitted by thetransmitting end, from the inputted data, the decoded signalinginformation provides to blocks requiring the signaling information.

More specifically, the signaling decoder 2013 extracts and decodes TPCdata and FIC data, which inserted and transmitted by the transmittingend, from the equalized data, and then the decoded TPC data and FIC dataoutputs to the operation controller 2000, the known sequence detector2004, the power controller 5000, the demodulator 2002, the equalizer2003, the block decoder 2005 and the RS frame decoder 2006. For example,the TPC data and FIC data is inserted in a signaling information regionof each data group, and then is transmitted to a receiving system.

The signaling decoder 2013 performs signaling decoding as an inverseprocess of the signaling encoder shown in FIG. 34, so as to extract TPCdata and FIC data. For example, the signaling decoder 2013 decodes theinputted data using the PCCC method and derandomizes the decoded data,thereby dividing the derandomized data into TPC data and FIC data. Atthis point, the signaling decoder 2013 performs RS-decoding on thedivided TPC data, so as to correct the errors occurring in the TPC data.Subsequently, the signaling decoder 2013 deinterleaves the divided FICdata and then performs RS-decoding on the deinterleaved FIC data, so asto correct the error occurring in the FIC data. The error-corrected TPCdata are then outputted to the operation controller 2000, the knownsequence detector 2004, and the power controller 5000.

The TPC data may also include a transmission parameter which is insertedinto the payload region of an OM packet by the service multiplexer 100,and then is transmitted to transmitter 200.

Herein, the TPC data may include RS frame information, SCCC information,M/H frame information, and so on, as shown in FIG. 35. The RS frameinformation may include RS frame mode information and RS code modeinformation. The SCCC information may include SCCC block modeinformation and SCCC outer code mode information. The M/H frameinformation may include M/H frame index information, and the TPC datamay include sub-frame count information, slot count information, paradeid information, SGN information, NoG information, and so on. The TPCdata may further include bonding region information, indicationinformation identifying a parade configured of a bonding data group anda parade configured of a general data group, information indicating abonding data group type, which is used in the corresponding parade,TNoG_NG, TNoG_BG, a rule for allocating the general data group and thebonding data group, and so on.

At this time, the signaling information area within the data group canbe identified using known data information output from the known datadetector 2004. More specifically, the first known data sequence (i.e.,first training sequence) is inserted into the last two segments of theM/H block B3, and the second known data sequence (i.e., second trainingsequence) is inserted between the second and third segments of the M/Hblock B4. At this time, since the second known data sequence is receivedsubsequently to the signaling information area, the signaling decoder2013 can decode the signaling information of the signaling informationarea by extracting the same from the data output from the demodulator2002 or the channel equalizer 2003.

The power controller 5000 is inputted the M/H frame-associatedinformation from the signaling decoder 2013, and controls power of thetuner and the demodulating unit. Alternatively, the power controller5000 is inputted a power control information from the operationcontroller 2000, and controls power of the tuner and the demodulatingunit.

According to the embodiment of the present invention, the powercontroller 5000 turns the power on only during a slot to which a slot ofthe parade including user-selected mobile service is assigned. The powercontroller 5000 then turns the power off during the remaining slots.

For example, it is assumed that data groups of a 1^(st) parade withNOG=3, a 2^(nd) parade with NOG=2, and a 3^(rd) parade with NOG=3 areassigned to one M/H frame, as shown in FIG. 37. It is also assumed thatthe user has selected a mobile service included in the 1^(st) paradeusing the keypad provided on the remote controller or terminal. In thiscase, the power controller 5000 turns the power on during a slot thatdata groups of the 1^(st) parade is assigned, as shown in FIG. 37, andturns the power off during the remaining slots, thereby reducing powerconsumption.

The demodulator 2002 uses the known data symbol sequence during thetiming and/or carrier recovery, thereby enhancing the demodulatingperformance. Similarly, the equalizer 2003 uses the known data so as toenhance the equalizing performance. Moreover, the decoding result of theblock decoder 2005 may be fed-back to the equalizer 2003, therebyenhancing the equalizing performance.

Demodulator and Known Sequence Detector

At this point, the transmitting system may receive a data frame (or VSBframe) including a data group which known data sequence (or trainingsequence) is periodically inserted therein, as shown in FIG. 5. Herein,the data group is divided into regions A to D, as shown in FIG. 5. Morespecifically, in the example of the present invention, each region A, B,C, and D are further divided into M/H blocks B4 to B7, M/H blocks B3 andB8, M/H blocks B2 and B9, M/H blocks B1 and B10, respectively. Accordingto another exemplary embodiment of the present invention, the receivingsystem of the present invention may receive first to sixth known datasequences and may also receive known data sequences inserted in thebonding region. At this point, as shown in FIG. 43 and FIG. 44, multipleshort known data sequences may be uniformly inserted in the bondingregion, and, as shown in FIG. 45, multiple long known data sequences maybe inserted in the bonding region in segment units.

Referring to FIG. 38 and FIG. 39, known data sequence having the samepattern are included in each known data section that is beingperiodically inserted. Herein, the length of the known data sequencehaving identical data patterns may be either equal to or different fromthe length of the entire (or total) known data sequence of thecorresponding known data section (or block). If the two lengths aredifferent from one another, the length of the entire known data sequenceshould be longer than the length of the known data sequence havingidentical data patterns. In this case, the same known data sequences areincluded in the entire known data sequence.

As described above, when the known data are periodically insertedin-between the mobile service data, the channel equalizer of thereceiving system may use the known data as training sequences, which maybe used as accurate discriminant values. According to another embodimentof the present invention, the channel equalizer estimates a channelimpulse response. Herein, the known data may be used in the process.According to yet another embodiment of the present invention, thechannel equalizer may use the known data for updating filtercoefficients (i.e., equalization coefficients).

Meanwhile, when known data sequence having the same pattern isperiodically inserted, each known data sequence may be used as a guardinterval in a channel equalizer according to the present invention.Herein, the guard interval prevents interference that occurs betweenblocks due to a multiple path channel. This is because the known datasequence located behind a mobile service data section (i.e., data block)may be considered as being copied in front of the mobile service datasection.

The above-described structure is referred to as a cyclic prefix. Thisstructure provides circular convolution in a time domain between a datablock transmitted from the transmitting system and a channel impulseresponse. Accordingly, this facilitates the channel equalizer of thereceiving system to perform channel equalization in a frequency domainby using a fast fourier transform (FFT) and an inverse fast fouriertransform (IFFT).

More specifically, when viewed in the frequency domain, the data blockreceived by the receiving system is expressed as a multiplication of thedata block and the channel impulse response. Therefore, when performingthe channel equalization, by multiplying the inverse of the channel inthe frequency domain, the channel equalization may be performed moreeasily.

The known sequence detector 2004 detects the position of the known databeing periodically inserted and transmitted as described above. At thesame time, the known sequence detector 2004 may also estimate initialfrequency offset during the process of detecting known data. In thiscase, the demodulator 2002 may estimate with more accuracy carrierfrequency offset from the information on the known data positioninformation and initial frequency offset estimation value, therebycompensating the estimated carrier frequency offset.

Meanwhile, when known data is transmitted, as shown in FIG. 5, the knownsequence detector 2004 detects a position of second known data region byusing known data of the second known data region that the same patternis repeated twice.

At this point, since the known sequence detector 2004 is well-informedof the data group structure, when the position of the second known dataregion is detected, the known sequence detector 2004 can estimatepositions of the first, third, fourth, fifth, and sixth known dataregions of a corresponding data group by counting symbols or segmentsbased upon the second known data region position. If the correspondingdata group is a data group including field synchronization segment, theknown sequence detector 2004 can estimate the position of the fieldsynchronization segment of the corresponding data group, which ispositioned chronologically before the second known data region, bycounting symbols or segments based upon the second known data regionposition. Also, the known sequence detector 2004 may estimate the knowndata position information and the field synchronization positioninformation from the parade including mobile service selected by a userbased on the M/H frame-associated information outputted from thesignaling decoder 2013. Furthermore, the known sequence detector 2004may estimate and output known data position information of a bondingregion.

At least one of the estimated known data poison information and fieldsynchronization information is provided to the demodulator 2002, thechannel equalizer 2003, the signaling decoder 2013, and the operationcontroller 2000.

Also, the known sequence detector 2004 may estimate initial frequencyoffset by using known data inserted in the second known data region(i.e., ACQ known data region). In this case, the demodulator 2002 mayestimate with more accuracy carrier frequency offset from theinformation on the known data position information and initial frequencyoffset estimation value, thereby compensating the estimated carrierfrequency offset.

Operation Controller

The operation controller 2000 receives the known data positioninformation and the transmission parameter information and then forwardsM/H frame time information, a presence or non-presence of a data groupof a selected parade, position information of known data within the datagroup, power control information and the like to each block of thedemodulating unit. The operation controller 2000, as shown in FIG. 49,controls operations of the demodulator 2002, the channel equalizer 2003,the block decoder 2005 and the RS frame decoder 2006. And, the operationcontroller 2000 is able to overall operations of the demodulating unit(not shown in the drawing). Moreover, the operation controller 2000 canbe implemented with the separate block or can be included within aprescribed one of the blocks of the demodulating unit shown in FIG. 49.

FIG. 50 is an overall block diagram of an operation controller 2000.According to an embodiment of the present invention, an operation of theoperation controller 2000 will be described for receiving a general datagroup when the general data group having a group format, as shown inFIG. 5, is applied to Equation 1 and then is transmitted in acorresponding slot.

Referring to FIG. 50, the operation controller 2000 can include a paradeID checker 3101, a frame synchronizer 3102, a parade mapper 3103, agroup controller 3104 and a known sequence indication controller 3105.

The operation controller 2000 receives known data position informationfrom the known sequence detector 2004 and receives transmissionparameter information from the signaling decoder 2013. The operationcontroller 2000 then generates a control signal necessary for ademodulating unit of a receiving system. For instance, the known dataposition information detected by the known sequence detector 2004 isinputted to the known sequence indication controller 3105. And, thetransmission parameter information (i.e., TPC data) decoded by thesignaling decoder 2013 is inputted to the parade ID checker 3101.

The parade ID checker 3101 compares a parade ID (parade ID selected by auser) contained in the user control signal to a parade ID inputted fromthe signaling decoder 2013. If the two parade IDs are not identical toeach other, the parade ID checker stands by until a next transmissionparameter is inputted from the signaling decoder 2013.

If the two parade IDs are identical to each other, the parade ID checker3101 outputs the transmission parameter information to the blocks withinthe operation controller 2000 and the overall system.

If it is checked that the parade ID in the transmission parameterinformation inputted to the parade ID checker 3101 is identical to theparade ID selected by a user, the parade ID checker 3101 outputsstarting_group_number (SGN) and number_of_groups (NOG) to the parademapper 3103, outputs sub_frame_number, slot_number andparade_repetition_cycle PRC) to the frame synchronizer 3102, outputsSCCC_block_mode, SCCC_outer_code_mode_A, SCCC_outer_code_mode_B,SCCC_outer_code_mode_C and SCCC_outer_code_mode_D to the block decoder2005, and outputs RS_frame_mode, RS_code_mode_primary andRs_code_mode_secondary to the RS frame decoder 2006.

The parade mapper 3103 receives the SGN and the NOG from the parade IDchecker as inputs, decides a general data group is carried by which oneof sixteen slots within a Sub-frame, and then outputs the correspondinginformation. Data group number transmitted every sub-frame is set to aninteger consecutive between SGN and (SGN+NOG−1). For instance, if SGN=3and NOG=4, four general data groups, of which group numbers are 3, 4, 5and 6, are transmitted for the corresponding sub-frames, respectively.The parade mapper finds a slot number j for transmitting a general datagroup according to Equation 1 with a group number i obtained from SGNand NOG.

In the above example, in case of SGN=3 and NOG=4, if they are insertedin Equation 1, slot numbers of groups transmitted according to the aboveformula sequentially become 12, 2, 6 and 10.

The parade mapper 3103 then outputs the found slot number information.

For example of outputting slot numbers, a method of using a bit vectorhaving 16 bits is available.

A bit vector SNi (i=0˜15) can be set to 1 if there exists a generalgroup transmitted for an i^(th) slot. A bit vector SNi (i=0˜15) can beset to 0 if a group transmitted for an i^(th) slot does not exist. And,this bit vector can be outputted as slot number information.

The frame synchronizer 3102 receives the sub_frame_number, slot-numberand PRC from the parade ID checker and then sends slot_counter andframe_mask signals as outputs. The slot_counter is the signal indicatinga slot_number at a current timing point at which a receiver isoperating. And, the frame_mask is the signal indicating whether acorresponding parade is transmitted for a current frame. The framesynchronizer 3102 performs a process for initializing slot_counter,sub_frame_number and frame_counter in receiving signaling informationinitially. A counter value of a current timing point is generated fromadding a delayed slot number L according to a time taken to decodesignaling from demodulation together with the signaling informationinputted in this process. After completion of the initializationprocess, slot_counter is updated every single slot period, updatessub_frame_counter every period of the slot_counter value, and updatesframe_counter every period of the sub_frame_counter. By referring to theframe_counter information and the PRC information, a frame_mask signalis generated. For example, if a corresponding parade is beingtransmitted for a current frame, ‘1’ is outputted as the frame_mask.Otherwise, it is able to output ‘0’.

The group controller 3104 receives the slot number information from theparade mapper 3103. The group controller 3104 receives the slot_counterand frame_mask information from the frame synchronizer 3102. The groupcontroller 3104 then outputs group_presence_indicator indicating whethera general data group is being transmitted. For instance, if the slotnumber information inputted from the parade mapper 3103 corresponds to12, 2, 6 and 10, when the frame_mask information inputted from the framesynchronizer 3102 is 1 and the slot_counter inputted from the framesynchronizer 3102 includes 2, 6, 10 and 12, ‘1’ is outputted as thegroup_presence_indicator. Otherwise, it is able to output 0.

The known sequence indication controller 3105 outputs positioninformation of another known data, group start position information andthe like with position information of specific inputted known data. Inthis case, since the known data are present at a previously appointedposition within the general data group, if position data of one of aplurality of known data sequences, it is able to know data positioninformation of another known sequence, data group start positioninformation and the like. The known sequence indication controller 3105can output known data and data group position information necessary forthe demodulating unit of the receiving system using thegroup_presence_indicator information only if the general data group istransmitted. Alternatively, the known sequence detector 2004 can performoperations of the known sequence indication controller 3105.

Channel Equalizer

The data demodulated by the demodulator 2002 by using the known data areinputted to the equalizer 2003. Additionally, the demodulated data mayalso be inputted to the known sequence detector 2004. At this point, ageneral data group that is inputted for the equalization process may bedivided into region A to region D, as shown in FIG. 5. Morespecifically, according to the embodiment of the present invention,region A includes M/H block B4 to M/H block B7, region B includes M/Hblock B3 and M/H block B8, region C includes M/H block B2 and M/H blockB9, and region D includes M/H block B1 and M/H block B10. In otherwords, one general data group is divided into M/H blocks from B1 to B10,each M/H block having the length of 16 segments. Also, a long trainingsequence (i.e., known data sequence) is inserted at the starting portionof the M/H blocks B4 to B8. Furthermore, two general data groups may beallocated (or assigned) to one VSB field. In this case, fieldsynchronization data are positioned in the 37^(th) segment of one of thetwo general data groups.

Meanwhile, the bonding data group is divided into regions A/B and abonding region. The bonding region includes 60 segments comprisingsegments that were used for transmitting the conventional main servicedata and segments that were used for transmitting the data of regionsC/D. Also, the bonding region further includes symbol positions ofregions C/D among the segments having the symbols of regions A/B andsymbols of regions C/D coexisting therein. In other words, in thesegment domain, the bonding region includes a region that was allocatedfor the main service data located between two contiguous data groups, aportion of region B, and regions C/D. Depending upon the segmentsincluded in the bonding region, the bonding region may be identified byhead bonding, tail bonding, and head-tail bonding.

The present invention may use known data, which have position andcontent information based upon an agreement between the transmittingsystem and the receiving system, and/or field synchronization data forthe channel equalization process.

The channel equalizer 2003 may perform channel equalization using aplurality of methods. According to the present invention, the channelequalizer 2003 uses known data and/or field synchronization data, so asto estimate a channel impulse response (CIR), thereby performing channelequalization.

Most particularly, an example of estimating the CIR in accordance witheach region within the general data group, which is hierarchicallydivided and transmitted from the transmitting system, and applying eachCIR differently will also be described herein.

At this point, a general data group(or bonding data group) can beassigned and transmitted a maximum the number of 4 in a VSB frame in thetransmitting system. In this case, all general data group do not includefield synchronization data. In the present invention, the general datagroup including the field synchronization data performschannel-equalization using the field synchronization data and knowndata. And the general data group not including the field synchronizationdata performs channel-equalization using the known data.

For example, the data of the M/H block B3 including the fieldsynchronization data performs channel-equalization using the CIRcalculated from the field synchronization data area and the CIRcalculated from the first known data area. Also, the data of the M/Hblocks B1 and B2 performs channel-equalization using the CIR calculatedfrom the field synchronization data area and the CIR calculated from thefirst known data area. Meanwhile, the data of the M/H blocks B1 to B3not including the field synchronization data performschannel-equalization using CIRS calculated from the first known dataarea and the third known data area.

As described above, the present invention uses the CIR estimated fromthe known data region in order to perform channel equalization on datawithin the general data group. At this point, each of the estimated CIRsmay be directly used in accordance with the characteristics of eachregion within the general data group. Alternatively, a plurality of theestimated CIRs may also be either interpolated or extrapolated so as tocreate a new CIR, which is then used for the channel equalizationprocess.

Herein, when a value F(Q) of a function F(x) at a particular point Q anda value F(S) of the function F(x) at another particular point S areknown, interpolation refers to estimating a function value of a pointwithin the section between points Q and S. Linear interpolationcorresponds to the simplest form among a wide range of interpolationoperations.

FIG. 51 illustrates an example of linear interpolation. Morespecifically, in a random function F(x), when given the values F(Q) andF(S) each from points x=Q and x=S, respectively, the approximate value{circumflex over (F)}(P) of the F(x) function at point x=P may beestimated by using Equation 7 below. In other words, since the values ofF(Q) and F(S) respective to each point x=Q and x=S are known (or given),a straight line passing through the two points may be calculated so asto obtain the approximate value {circumflex over (F)}(P) of thecorresponding function value at point P. At this point, the straightline passing through points (Q,F(Q)) and (S,F(S)) may be obtained byusing Equation 7 below.

$\begin{matrix}{{\hat{F}(x)} = {{\frac{{F(S)} - {F(Q)}}{S - Q}( {x - Q} )} + {F(Q)}}} & {{Equation}\mspace{14mu} 7}\end{matrix}$

Accordingly, Equation 8 below shows the process of substituting p for xin Equation 7, so as to calculate the approximate value {circumflex over(F)}(P) of the function value at point P.

$\begin{matrix}{{\hat{F}(P)} = {{\frac{{F(S)} - {F(Q)}}{S - Q}( {P - Q} )} + {F(Q)}}} & {{Equation}\mspace{14mu} 8} \\{{\hat{F}(P)} = {{\frac{S - P}{S - Q}{F(Q)}} + {\frac{( {P - Q} )}{S - Q}{F(S)}}}} & \;\end{matrix}$

The linear interpolation method of Equation 8 is merely the simplestexample of many other linear interpolation methods. Therefore, since anyother linear interpolation method may be used, the present inventionwill not be limited only to the examples given herein.

Alternatively, when a value F(Q) of a function F(x) at a particularpoint Q and a value F(S) of the function F(x) at another particularpoint S are known (or given), extrapolation refers to estimating afunction value of a point outside of the section between points Q and S.Herein, the simplest form of extrapolation corresponds to linearextrapolation.

FIG. 52 illustrates an example of linear extrapolation. As describedabove, for linear extrapolation as well as linear interpolation, in arandom function F(x), when given the values F(Q) and F(S) each frompoints x=Q and x=S, respectively, the approximate value {circumflex over(F)}(P) of the corresponding function value at point P may be obtainedby calculating a straight line passing through the two points. Herein,linear extrapolation is the simplest form among a wide range ofextrapolation operations. Similarly, the linear extrapolation describedherein is merely exemplary among a wide range of possible extrapolationmethods. And, therefore, the present invention is not limited only tothe examples set forth herein.

FIG. 53 illustrates a block diagram of a channel equalizer according toan embodiment of the present invention. The channel equalizer as shownin FIG. 53 is effective for channel equalization of a general data grouphaving a group format as shown in FIG. 5 or a bonding data group thatlong known data sequences are positioned in a bonding region as shown inFIG. 45.

Referring to FIG. 53, the channel equalizer includes a first frequencydomain converter 4100, a channel estimator 4110, a second frequencydomain converter 4121, a coefficient calculator 4122, a distortioncompensator 4130, and a time domain converter 4140. Herein, the channelequalizer may further include a remaining carrier phase error remover, anoise canceller (NC), and a decision unit.

The first frequency domain converter 4100 includes an overlap unit 4101overlapping inputted data, and a fast fourier transform (FFT) unit 4102converting the data outputted from the overlap unit 4101 to frequencydomain data.

The channel estimator 4110 includes a CIR estimator 4111, a firstcleaner 4113, a CIR calculator 4114, a second cleaner, and azero-padding unit. herein, the channel estimator 4110 may furtherinclude a phase compensator compensating a phase of the CIR whichestimated in the CIR estimator 4111.

The second frequency domain converter 4121 includes a fast fouriertransform (FFT) unit converting the CIR being outputted from the channelestimator 4110 to frequency domain CIR.

The time domain converter 4140 includes an IFFT unit 4141 converting thedata having the distortion compensated by the distortion compensator4130 to time domain data, and a save unit 4142 extracting only validdata from the data outputted from the IFFT unit 4141. The output datafrom the save unit 4142 corresponds to the channel-equalized data.

If the remaining carrier phase error remover is connected to an outputterminal of the time domain converter 4140, the remaining carrier phaseerror remover estimates the remaining carrier phase error included inthe channel-equalized data, thereby removing the estimated error. If thenoise remover is connected to an output terminal of the time domainconverter 4140, the noise remover estimates noise included in thechannel-equalized data, thereby removing the estimated noise.

More specifically, the receiving data demodulated in FIG. 53 areoverlapped by the overlap unit 4101 of the first frequency domainconverter 4100 at a pre-determined overlapping ratio, which are thenoutputted to the FFT unit 4102. The FFT unit 4102 converts theoverlapped time domain data to overlapped frequency domain data throughby processing the data with FFT. Then, the converted data are outputtedto the distortion compensator 4130.

The distortion compensator 4130 performs a complex number multiplicationon the overlapped frequency domain data outputted from the FFT unit 4102included in the first frequency domain converter 4100 and theequalization coefficient calculated from the coefficient calculator4122, thereby compensating the channel distortion of the overlapped dataoutputted from the FFT unit 4102. Thereafter, the compensated data areoutputted to the IFFT unit 4141 of the time domain converter 4140. TheIFFT unit 4141 performs IFFT on the overlapped data having the channeldistortion compensated, thereby converting the overlapped data to timedomain data, which are then outputted to the save unit 4142. The saveunit 4142 extracts valid data from the data of the channel-equalized andoverlapped in the time domain, and outputs the extracted valid data.

Meanwhile, the received data are inputted to the overlap unit 4101 ofthe first frequency domain converter 4100 included in the channelequalizer and, at the same time, inputted to the CIR estimator 4111 ofthe channel estimator 4110.

The CIR estimator 4111 uses a training sequence, for example, data beinginputted during the known data section and the known data in order toestimate the CIR. If the data to be channel-equalizing is the datawithin the general data group (or bonding data group) including fieldsynchronization data, the training sequence using in the CIR estimator4111 may become the field synchronization data and known data.Meanwhile, if the data to be channel-equalizing is the data within thegeneral data group (or bonding data group) not including fieldsynchronization data, the training sequence using in the CIR estimator4111 may become only the known data.

For example, the CIR estimator 4111 estimates CIR using the known datacorrespond to reference known data generated during the known datasection by the receiving system in accordance with an agreement betweenthe receiving system and the transmitting system. For this, the CIRestimator 4111 is provided known data position information from theknown sequence detector 2004. Also, if the data to be channel-equalizingis the data within the general data group (or bonding data group)including field synchronization data, the CIR estimator 4111 mayestimate CIR (CIR_FS) using the field synchronization data correspond toreference field synchronization data generated during the fieldsynchronization data section by the receiving system in accordance withan agreement between the receiving system and the transmitting system.For this, the CIR estimator 4111 is provided field synchronization dataposition information from the known sequence detector 2004.

The estimated CIR passes through the first cleaner (or pre-CIR cleaner)4113 or bypasses the first cleaner 4113, thereby being inputted to theCIR calculator (or CIR interpolator-extrapolator) 4114. The CIRcalculator 4114 either interpolates or extrapolates an estimated CIR,which is then outputted to the second cleaner (or post-CIR cleaner)4115.

The first cleaner 4113 may or may not operate depending upon whether theCIR calculator 4114 interpolates or extrapolates the estimated CIR. Forexample, if the CIR calculator 4114 interpolates the estimated CIR, thefirst cleaner 4113 does not operate. Conversely, if the CIR calculator4114 extrapolates the estimated CIR, the first cleaner 4113 operates.

More specifically, the CIR estimated from the known data includes achannel element that is to be obtained as well as a jitter elementcaused by noise. Since such jitter element deteriorates the performanceof the equalizer, it preferable that a coefficient calculator 4122removes the jitter element before using the estimated CIR. Therefore,according to the embodiment of the present invention, each of the firstand second cleaners 4113 and 4115 removes a portion of the estimated CIRhaving a power level lower than the predetermined threshold value (i.e.,so that the estimated CIR becomes equal to ‘0’). Herein, this removalprocess will be referred to as a “CIR cleaning” process.

The CIR calculator 4114 performs CIR interpolation by multiplying CIRsestimated from the CIR estimator 4111 by each of coefficients, therebyadding the multiplied values. At this point, some of the noise elementsof the CIR may be added to one another, thereby being cancelled.Therefore, when the CIR calculator 4114 performs CIR interpolation, theoriginal (or initial) CIR having noise elements remaining therein. Inother words, when the CIR calculator 4114 performs CIR interpolation,the estimated CIR bypasses the first cleaner 4113 and is inputted to theCIR calculator 4114. Subsequently, the second cleaner 4115 cleans theCIR interpolated by the CIR interpolator-extrapolator 4114.

Conversely, the CIR calculator 4114 performs CIR extrapolation by usinga difference value between two CIRs, so as to estimate a CIR positionedoutside of the two CIRs. Therefore, in this case, the noise element israther amplified. Accordingly, when the CIR calculator 4114 performs CIRextrapolation, the CIR cleaned by the first cleaner 4113 is used. Morespecifically, when the CIR calculator 4114 performs CIR extrapolation,the extrapolated CIR passes through the second cleaner 4115, therebybeing inputted to the zero-padding unit 4116.

Meanwhile, when a second frequency domain converter (or fast fouriertransform (FFT2)) 4121 converts the CIR, which has been cleaned andoutputted from the second cleaner 4115, to a frequency domain, thelength and of the inputted CIR and the FFT size may not match (or beidentical to one another). In other words, the CIR length may be smallerthan the FFT size. In this case, the zero-padding unit 4116 adds anumber of zeros ‘0’s corresponding to the difference between the FFTsize and the CIR length to the inputted CIR, thereby outputting theprocessed CIR to the second frequency domain converter (FFT2) 4121.Herein, the zero-padded CIR may correspond to one of the interpolatedCIR, extrapolated CIR, and the CIR estimated in the known data section.

The second frequency domain converter 4121 performs FFT on the CIR beingoutputted from the zero padding unit 4116, thereby converting the CIR toa frequency domain CIR. Then, the second frequency domain converter 4121outputs the converted CIR to the coefficient calculator 4122.

The coefficient calculator 4122 uses the frequency domain CIR beingoutputted from the second frequency domain converter 4121 to calculatethe equalization coefficient. Then, the coefficient calculator 4122outputs the calculated coefficient to the distortion compensator 4130.Herein, for example, the coefficient calculator 4122 calculates achannel equalization coefficient of the frequency domain that canprovide minimum mean square error (MMSE) from the CIR of the frequencydomain, which is outputted to the distortion compensator 4130.

The distortion compensator 4130 performs a complex number multiplicationon the overlapped data of the frequency domain being outputted from theFFT unit 4102 of the first frequency domain converter 4100 and theequalization coefficient calculated by the coefficient calculator 4122,thereby compensating the channel distortion of the overlapped data beingoutputted from the FFT unit 4102.

FIG. 54 illustrates a channel equalizer according to another exemplaryembodiment of the present invention. The channel equalizer of FIG. 54 ismore efficient for channel equalization, when performing channelequalization on the general data group having a group format, as shownin FIG. 5, or when performing channel equalization on a bonding datagroup having short known data sequences uniformly assigned to a bondingregion as shown in FIG. 43 or FIG. 44.

According to the embodiment of the present invention, in case of ageneral data group, the channel equalizer of FIG. 54 differentlyperforms channel equalization on regions A/B and regions C/D, and, incase of a bonding data group, the channel equalizer of FIG. 54differently performs channel equalization on regions A/B and the bondingregion.

According to the embodiment of the present invention, in case of thegeneral data groups, channel equalization of an indirect equalizationscheme is performed by using an overall & save method on the data ofregions A/B, and channel equalization of a direct equalization scheme isperformed by using an overall & save method on the data of regions C/D.Also, according to the embodiment of the present invention, in case ofthe bonding data group, channel equalization of an indirect equalizationscheme is performed by using an overall & save method on the data ofregions A/B, and channel equalization of a direct equalization scheme isperformed by using an overall & save method on the data of bondingregion. More specifically, in regions A/B of the general data group andthe bonding data group, channel equalization may be performed by usinglong known data sequences, and in regions C/D of the general data groupand in the bonding region of the bonding data group, the channelequalization may be performed by using an equalized decision value.

The channel equalizer of FIG. 54 includes a frequency domain converter4100, a distortion compensator 4130, a time domain converter 4140, afirst coefficient calculating unit 4300, a second coefficientcalculating unit 4400, and a coefficient select unit 4500.

The frequency domain converter 4100 includes an overlap unit 4101overlapping inputted data, and a first FFT (Fast Fourier Transform) unit4102 converting the data outputted from the overlap unit 4101 tofrequency domain data.

Any device performing multiplication of complex numbers may be used asthe distortion compensator 4130.

The time domain converter 4140 includes an IFFT unit 4141 converting thedata having the distortion compensated by the distortion compensator4130 to time domain data, and a save unit 4142 extracting only validdata from the data outputted from the IFFT unit 4141. The output data ofthe save unit 4142 correspond to the channel-equalized data. At thispoint, a remaining carrier wave phase error remover is further providedat the output end of the time domain converter 4140. Thus, the remainingcarrier wave phase error included in the channel equalized data may beestimated and removed. Furthermore, a noise remover may also be furtherprovided at the output end of the time domain converter 4140, therebyestimating and removing noise included in the channel equalized data.

The first coefficient calculating unit 4300 includes a CIR estimator4301, a CIR Interpolator/Extrapolator 4302, a second FFT unit 4303, anda coefficient calculator 4304.

The second coefficient calculating unit 4400 includes a decision unit4401, a select unit 4402, a subtractor 4403, a zero-padding unit 4404, athird FFT unit 4405, and a coefficient updater 4406.

More specifically, referring to FIG. 54, the overlap unit 4101 of thefrequency domain converter 4100 overlaps the demodulated and inputteddata to a predetermined overlapping ratio and then outputs theoverlapped data to the first FFT unit 4102. The first FFT unit 4102converts (or transforms) the overlapped data of the time domain tooverlapped data of the frequency domain by using fast fourier transform(FFT). Then, the converted data are outputted to the distortioncompensator 4103 and the coefficient updater 4406 of the secondcoefficient calculating unit 4400.

The distortion converter 4103 performs complex multiplication on theequalization coefficient being selected and outputted from thecoefficient select unit 4500 and the overlapped data of the frequencydomain being outputted from the first FFT unit 4102 of the frequencydomain converter 4100, thereby compensating the channel distortion ofthe overlapped data being outputted from the first FFT unit 4102.Thereafter, the distortion-compensated data are outputted to the IFFTunit 4104.

The IFFT unit 4104 of the time domain converter 4140 performs IFFT onthe distortion-compensated data, thereby converting the compensated datato overlapped time domain data. The converted overlapped data are thenoutputted to the save unit 4142. The save unit 4142 extracts only thevalid data from the overlapped data of the channel-equalized timedomain, which are then outputted for data decoding and, at the sametime, outputted to the subtractor 4403 of the second coefficientcalculating unit 4400 in order to update the coefficient.

The CIR estimator 4301 of the first coefficient calculating unit 4300uses a training sequence to estimate the CIR. Then, the estimated CIR isoutputted to the CIR interpolator/extrapolator 4302.

If the data that is to be channel-equalized correspond to data includedin a general data group (or bonding data group) including fieldsynchronization, the training sequence used in the CIR estimator 4301may correspond to the field synchronization data and the known data.However, if the data that is to be channel-equalized correspond to dataincluded in a general data group (or bonding data group) that does notinclude field synchronization, the training sequence may only correspondto the known data.

For example, the CIR estimator 4301 estimates channel impulse response(CIR) by using data received during a known data section and referenceknown data, which are generated by the receiving system based upon apre-arranged agreement between the transmitting system and the receivingsystem. In order to do so, the CIR estimator 4301 receives Known DataPosition Information from the known sequence detector 2004.

Also, if the data group includes field synchronization, the CIRestimator 4301 may estimate a channel impulse response (CIR_FS) by usingdata being received during a field synchronization section and referencefield synchronization data, which are generated by the receiving systembased upon a pre-arranged agreement between the transmitting system andthe receiving system. In order to do so, the channel estimator 4301 mayreceive Field Sync Position Information from the known sequence detector2004. The CIR that is estimated as described above is then outputted tothe CIR interpolator/extrapolator 4302.

The CIR interpolator/extrapolator 4302 performs interpolation orextrapolation on the estimated CIR and then outputs the interpolated orextrapolated CIR to the second FFT unit 4303.

At this point, a first cleaner (not shown) may be further provided at afront end of the CIR interpolator/extrapolator 4302, and a secondcleaner (not shown) may be further provided at a rear end of the CIRinterpolator/extrapolator 4302.

For example, if the CIR interpolator/extrapolator 4302 performsinterpolation on the estimated CIR by using the estimated CIR, the firstcleaner is not operated, and, if the CIR interpolator/extrapolator 4302performs extrapolation on the estimated CIR by using the estimated CIR,the first cleaner is operated. In other words, the CIR estimated fromthe known data not only includes the channel element that is to beobtained, but also includes jitter elements caused by noise. Such jitterelement results in a deterioration of the performance of the channelequalizer. Accordingly, it is preferable to remove the jitter elementbefore using the CIR in the coefficient calculator 4406. Therefore, inthe examples given herein, the first and second cleaners respectivelyremove portions of the CIR element having a power level equal to andlower than a pre-determined threshold value from the CIR element (i.e.,the first and second cleaners respectively process the CIR element to‘0’). Herein, the above-described process is referred to as a CIRcleaning process.

According to an embodiment of the present invention, in the CIRinterpolator/extrapolator 4302, the CIR interpolation process isperformed by multiplying and adding coefficients to each of the two CIRestimated by the CIR estimator 4301. At this point, a portion of thenoise element of each CIR is added to one another, thereby canceling oneanother. Therefore, when the CIR interpolator/extrapolator 4302 performsCIR interpolation, the original CIR having the noise element remainingtherein is used.

According to another embodiment of the present invention, in the CIRinterpolator/extrapolator 4302, the CIR extrapolation process isperformed by using a difference value between two CIRs estimated by theCIR estimator 4301 so as to estimate a CIR located outside of the twoestimated CIRs. In this case, the noise element is rather amplified.Therefore, when the CIR interpolator/extrapolator 4302 performs CIRinterpolation, the CIR cleaned by the first cleaner is used.

The second FFT unit 4303 performs FFT on the CIR of the time domain,which is being inputted, so as to convert the time domain CIR to afrequency domain CIR, which is then outputted to the coefficientcalculator 4304.

The coefficient calculator 4304 then uses the converted frequency domainCIR to calculate the equalization coefficient, thereby outputting thecalculated coefficient to the coefficient select unit 4500. At thispoint, the coefficient calculator 4304 calculates a channel equalizationcoefficient of the frequency domain that can provide a Minimum MeanSquare Error (MMSE) from the frequency domain CIR. Then, the calculatedcoefficient may be outputted to the coefficient select unit 4500.

The decision unit 4401 of the second coefficient calculating unit 4400selects one of a plurality of decision values, e.g., 8 decision values,that is most approximate to the equalized data and outputs the selecteddecision value to the select unit 4402. Based upon a select signal (S2),the select unit 4402 selects the decision value of the decision unit4401, in case the data section is not a known data section.Alternatively, in a known data section, the select unit 4402 selects aknown data symbol and outputs the selected known data symbol to thesubtractor 4403. The subtractor 4403 subtracts the output of the timedomain converter 4400 from the output of the select unit 4402 so as tocalculate (or obtain) an error value. Thereafter, the calculated errorvalue is outputted to the zero-padding unit 4404.

The zero-padding unit 4404 adds (or inserts) the same amount of zeros(0) corresponding to the overlapped amount of the received data in theinputted error. Then, the error extended with zeros (0) is outputted tothe third FFT unit 4405. The third FFT unit 4405 converts the error ofthe time domain having zeros (0) added (or inserted) therein, to theerror of the frequency domain. Thereafter, the converted error isoutputted to the coefficient update unit 4406.

The coefficient update unit 4406 uses the data of the frequency domain,which are outputted from the first FFT unit 4102, and the error beingoutputted from the third FFT unit 4405 so as to update the previousequalization coefficient. Thereafter, the updated equalizationcoefficient is outputted to the coefficient select unit 4500. At thispoint, the updated equalization coefficient is stored so as that it canbe used as a previous equalization coefficient in a later process.

Based upon the select signal (S1), the coefficient select unit 4500 mayselect an equalization coefficient being outputted from the firstcoefficient calculating unit 4300, or may select an equalizationcoefficient being outputted from the second coefficient calculating unit4400, thereby outputting the selected equalization coefficient to thedistortion compensator 4130. According to the embodiment of the presentinvention, the select signal (S1) may be provided from an operationcontroller 2000. For example, the select signal (S1) is generated sothat data of regions A/B of a general data group and data of regions A/Bof a bonding data group can be channel-equalized by using theequalization coefficient calculated by the first coefficient calculatingunit 4300, and so that data of regions C/D of a general data group anddata of a bonding region of the bonding data group can bechannel-equalized by using the equalization coefficient calculated bythe second coefficient calculating unit 4400.

Meanwhile, according to another embodiment of the present invention,channel distortion occurring in data of a bonding region within thebonding data group may also be compensated by using an adaptive channelequalizer. An equalizing filter included in the adaptive equalizerallows the equalization coefficients to converge by using a long knowndata sequence inserted in regions A/B. Then, in the bonding region, theconverged equalization coefficient is updated by using a known datasymbol. Thereafter, decision values for symbols other than the knowndata symbol are fed-back. Thus, the equalization coefficients may beupdated, or the corresponding coefficients may be on hold without beingupdated.

Block Decoder

Meanwhile, if the data being inputted to the block decoder 2005, afterbeing channel-equalized by the equalizer 2003, correspond to the datahaving both block encoding and trellis encoding performed thereon (i.e.,the data within the RS frame, the signaling information data, etc.) bythe transmitting system, trellis decoding and block decoding processesare performed on the inputted data as inverse processes of thetransmitting system. Alternatively, if the data being inputted to theblock decoder 2005 correspond to the data having only trellis encodingperformed thereon (i.e., the main service data), and not the blockencoding, only the trellis decoding process is performed on the inputteddata as the inverse process of the transmitting system.

The trellis decoded and block decoded data by the block decoder 2005 arethen outputted to the RS frame decoder 2006. More specifically, theblock decoder 2005 removes the known data, data used for trellisinitialization, and signaling information data, MPEG header, which havebeen inserted in the general data group (or bonding data group), and theRS parity data, which have been added by the RS encoder/non-systematicRS encoder or non-systematic RS encoder of the transmitting system.Then, the block decoder 2005 outputs the processed data to the RS framedecoder 2006. Herein, the removal of the data may be performed beforethe block decoding process, or may be performed during or after theblock decoding process.

Meanwhile, the data trellis-decoded by the block decoder 2005 areoutputted to the data deinterleaver of the main service data processor2008. At this point, the data being trellis-decoded by the block decoder2005 and outputted to the data deinterleaver may not only include themain service data but may also include the data within the RS frame andthe signaling information. Furthermore, the RS parity data that areadded by the transmitting system after the pre-processor 230 may also beincluded in the data being outputted to the data deinterleaver.

According to another embodiment of the present invention, data that arenot processed with block decoding and only processed with trellisencoding by the transmitting system may directly bypass the blockdecoder 2005 so as to be outputted to the data deinterleaver. In thiscase, a trellis decoder should be provided before the datadeinterleaver. More specifically, if the inputted data correspond to thedata having only trellis encoding performed thereon and not blockencoding, the block decoder 2005 performs Viterbi (or trellis) decodingon the inputted data so as to output a hard decision value or to performa hard-decision on a soft decision value, thereby outputting the result.

Meanwhile, if the inputted data correspond to the data having both blockencoding process and trellis encoding process performed thereon, theblock decoder 2005 outputs a soft decision value with respect to theinputted data.

In other words, if the inputted data correspond to data being processedwith block encoding by the block processor 302 and being processed withtrellis encoding by the trellis encoding module 256, in the transmittingsystem, the block decoder 2005 performs a decoding process and a trellisdecoding process on the inputted data as inverse processes of thetransmitting system. At this point, the RS frame encoder of thepre-processor included in the transmitting system may be viewed as anouter (or external) encoder. And, the trellis encoder may be viewed asan inner (or internal) encoder. When decoding such concatenated codes,in order to allow the block decoder 2005 to maximize its performance ofdecoding externally encoded data, the decoder of the internal codeshould output a soft decision value.

FIG. 55 illustrates a detailed block diagram of the block decoder 2005according to an embodiment of the present invention. Referring to FIG.55, the block decoder 2005 includes a feedback controller 4010, an inputbuffer 4011, a trellis decoding unit (or 12-way trellis coded modulation(TCM) decoder or inner decoder) 4012, a symbol-byte converter 4013, anouter block extractor 4014, a feedback deformatter 4015, a symboldeinterleaver 4016, an outer symbol mapper 4017, a symbol decoder 4018,an inner symbol mapper 4019, a symbol interleaver 4020, a feedbackformatter 4021, and an output buffer 4022. Herein, just as in thetransmitting system, the trellis decoding unit 4012 may be viewed as aninner (or internal) decoder. And, the symbol decoder 4018 may be viewedas an outer (or external) decoder.

The input buffer 4011 temporarily stores the mobile service data symbolsbeing channel-equalized and outputted from the equalizer 2003. (Herein,the mobile service data symbols may include symbols corresponding to thesignaling information, RS parity data symbols and CRC data symbols addedduring the encoding process of the RS frame.) Thereafter, the inputbuffer 4011 repeatedly outputs the stored symbols for M number of timesto the trellis decoding unit 4012 in a turbo block (TDL) size requiredfor the turbo decoding process.

The turbo decoding length (TDL) may also be referred to as a turboblock. Herein, a TDL should include at least one SCCC block size.Therefore, as defined in FIG. 5, when it is assumed that one M/H blockis a 16-segment unit, and that a combination of 10 M/H blocks form oneSCCC block, a TDL should be equal to or larger than the maximum possiblecombination size. For example, when it is assumed that 2 M/H blocks formone SCCC block, the TDL may be equal to or larger than 32 segments(i.e., 828×32=26496 symbols). Herein, M indicates a number ofrepetitions for turbo-decoding pre-decided by the feed-back controller4010. At this point, when it is assumed that the data group correspondsto a general data group, and that one SCCC block is configured by using2 M/H blocks, M/H block B1 and M/H block B6 may be combined to configurean SCCC block, M/H block B2 and M/H block B7 may be combined toconfigure an SCCC block, M/H block B3 and M/H block B8 may be combinedto configure an SCCC block, M/H block B4 and M/H block B9 may becombined to configure an SCCC block, and M/H block B5 and M/H block B10may be combined to configure an SCCC block. Also, in case the data groupcorresponds to a bonding data group, M/H block B1 and M/H block B9 maybe combined to configure an SCCC block, and M/H block B2 and M/H blockB10 may be combined to configure an SCCC block. Furthermore, accordingto the embodiment of the present invention, the block decoding processmay be performed in SCCC block units.

Also, M represents a number of repetitions of the turbo decodingprocess, the number being predetermined by the feedback controller 4010.

Additionally, among the values of symbols being channel-equalized andoutputted from the equalizer 2003, the input symbol values correspondingto a section having no mobile service data symbols (including RS paritydata symbols during RS frame encoding and CRC data symbols) includedtherein, bypass the input buffer 4011 without being stored. Morespecifically, since trellis-encoding is performed on input symbol valuesof a section wherein SCCC block-encoding has not been performed, theinput buffer 4011 inputs the inputted symbol values of the correspondingsection directly to the trellis encoding module 4012 without performingany storage, repetition, and output processes. The storage, repetition,and output processes of the input buffer 4011 are controlled by thefeedback controller 4010. Herein, the feedback controller 4010 refers toSCCC-associated information (e.g., SCCC block mode and SCCC outer codemode), which are outputted from the signaling decoder 2013 or theoperation controller 2000, in order to control the storage and outputprocesses of the input buffer 4011.

The trellis decoding unit 4012 includes a 12-way TCM decoder. Herein,the trellis decoding unit 4012 performs 12-way trellis decoding asinverse processes of the 12-way trellis encoder.

More specifically, the trellis decoding unit 4012 receives a number ofoutput symbols of the input buffer 4011 and soft-decision values of thefeedback formatter 4021 equivalent to each TDL, so as to perform the TCMdecoding process.

At this point, based upon the control of the feedback controller 4010,the soft-decision values outputted from the feedback formatter 4021 arematched with a number of mobile service data symbol places so as to bein a one-to-one (1:1) correspondence. Herein, the number of mobileservice data symbol places is equivalent to the TDL being outputted fromthe input buffer 4011.

More specifically, the mobile service data being outputted from theinput buffer 4011 are matched with the turbo decoded data beinginputted, so that each respective data place can correspond with oneanother. Thereafter, the matched data are outputted to the trellisdecoding unit 4012. For example, if the turbo decoded data correspond tothe third symbol within the turbo block, the corresponding symbol (ordata) is matched with the third symbol included in the turbo block,which is outputted from the input buffer 4011. Subsequently, the matchedsymbol (or data) is outputted to the trellis decoding unit 4012.

In order to do so, while the regressive turbo decoding is in process,the feedback controller 4010 controls the input buffer 4011 so that theinput buffer 4011 stores the corresponding turbo block data. Also, bydelaying data (or symbols), the soft decision value (e.g., LLR) of thesymbol outputted from the symbol interleaver 4020 and the symbol of theinput buffer 4011 corresponding to the same place (or position) withinthe block of the output symbol are matched with one another to be in aone-to-one correspondence. Thereafter, the matched symbols arecontrolled so that they can be inputted to the TCM decoder through therespective path. This process is repeated for a predetermined number ofturbo decoding cycle periods. Then, the data of the next turbo block areoutputted from the input buffer 4011, thereby repeating the turbodecoding process.

The output of the trellis decoding unit 4012 signifies a degree ofreliability of the transmission bits configuring each symbol. Forexample, in the transmitting system, since the input data of the trellisencoding module correspond to two bits as one symbol, a log likelihoodratio (LLR) between the likelihood of a bit having the value of ‘1’ andthe likelihood of the bit having the value of ‘0’ may be respectivelyoutputted (in bit units) to the upper bit and the lower bit. Herein, thelog likelihood ratio corresponds to a log value for the ratio betweenthe likelihood of a bit having the value of ‘1’ and the likelihood ofthe bit having the value of ‘0’. Alternatively, a LLR for the likelihoodof 2 bits (i.e., one symbol) being equal to “00”, “01”, “10”, and “11”may be respectively outputted (in symbol units) to all 4 combinations ofbits (i.e., 00, 01, 10, 11). Consequently, this becomes the softdecision value that indicates the degree of reliability of thetransmission bits configuring each symbol. A maximum a posterioriprobability (MAP) or a soft-out Viterbi algorithm (SOYA) may be used asa decoding algorithm of each TCM decoder within the trellis decodingunit 4012.

The output of the trellis decoding unit 4012 is inputted to thesymbol-byte converter 4013 and the outer block extractor 4014.

The symbol-byte converter 4013 performs a hard-decision process of thesoft decision value that is trellis decoded and outputted from thetrellis decoding unit 4012. Thereafter, the symbol-byte converter 4013groups 4 symbols into byte units, which are then outputted to the datadeinterleaver of the main service data processor 2008 of FIG. 49. Morespecifically, the symbol-byte converter 4013 performs hard-decision inbit units on the soft decision value of the symbol outputted from thetrellis decoding unit 4012. Therefore, the data processed withhard-decision and outputted in bit units from the symbol-byte converter4013 not only include main service data, but may also include mobileservice data, known data, RS parity data, and MPEG headers.

Among the soft decision values of TDL size of the trellis decoding unit4012, the outer block extractor 4014 identifies the soft decision valuesof B size of corresponding to the mobile service data symbols (whereinsymbols corresponding to signaling information, RS parity data symbolsthat are added during the encoding of the RS frame, and CRC data symbolsare included) and outputs the identified soft decision values to thefeedback deformatter 4015.

The feedback deformatter 4015 changes the processing order of the softdecision values corresponding to the mobile service data symbols. Thisis an inverse process of an initial change in the processing order ofthe mobile service data symbols, which are generated during anintermediate step, wherein the output symbols outputted from the blockprocessor 302 of the transmitting system are being inputted to thetrellis encoding module 256 (e.g., when the symbols pass through thegroup formatter, the data deinterleaver, the packet formatter, and thedata interleaver). Thereafter, the feedback deformatter 2015 performsreordering of the process order of soft decision values corresponding tothe mobile service data symbols and, then, outputs the processed mobileservice data symbols to the symbol deinterleaver 4016.

This is because a plurality of blocks exist between the block processor302 and the trellis encoding module 256, and because, due to theseblocks, the order of the mobile service data symbols being outputtedfrom the block processor 302 and the order of the mobile service datasymbols being inputted to the trellis encoding module 256 are notidentical to one another. Therefore, the feedback deformatter 4015reorders (or rearranges) the order of the mobile service data symbolsbeing outputted from the outer block extractor 4014, so that the orderof the mobile service data symbols being inputted to the symboldeinterleaver 4016 matches the order of the mobile service data symbolsoutputted from the block processor 302 of the transmitting system. Thereordering process may be embodied as one of software, middleware, andhardware.

The symbol deinterleaver 4016 performs deinterleaving on the mobileservice data symbols having their processing orders changed andoutputted from the feedback deformatter 4015, as an inverse process ofthe symbol interleaving process of the symbol interleaver 514 includedin the transmitting system. The size of the block used by the symboldeinterleaver 4016 during the deinterleaving process is identical tointerleaving size of an actual symbol (i.e., B) of the symbolinterleaver 514, which is included in the transmitting system. This isbecause the turbo decoding process is performed between the trellisdecoding unit 4012 and the symbol decoder 4018. Both the input andoutput of the symbol deinterleaver 4016 correspond to soft decisionvalues, and the deinterleaved soft decision values are outputted to theouter symbol mapper 4017.

The operations of the outer symbol mapper 4017 may vary depending uponthe structure and coding rate of the convolution encoder 513 included inthe transmitting system. For example, when data are ½-rate encoded bythe convolution encoder 513 and then transmitted, the outer symbolmapper 4017 directly outputs the input data without modification. Inanother example, when data are ¼-rate encoded by the convolution encoder513 and then transmitted, the outer symbol mapper 4017 converts theinput data so that it can match the input data format of the symboldecoder 4018. For this, the outer symbol mapper 4017 may be inputtedSCCC-associated information (i.e., SCCC block mode and SCCC outer codemode) from the signaling decoder 2013. Then, the outer symbol mapper4017 outputs the converted data to the symbol decoder 4018.

The symbol decoder 4018 (i.e., the outer decoder) receives the dataoutputted from the outer symbol mapper 4017 and performs symbol decodingas an inverse process of the convolution encoder 513 included in thetransmitting system. At this point, two different soft decision valuesare outputted from the symbol decoder 4018. One of the outputted softdecision values corresponds to a soft decision value matching the outputsymbol of the convolution encoder 513 (hereinafter referred to as a“first decision value”). The other one of the outputted soft decisionvalues corresponds to a soft decision value matching the input bit ofthe convolution encoder 513 (hereinafter referred to as a “seconddecision value”).

More specifically, the first decision value represents a degree ofreliability the output symbol (i.e., 2 bits) of the convolution encoder513. Herein, the first soft decision value may output (in bit units) aLLR between the likelihood of 1 bit being equal to ‘1’ and thelikelihood of 1 bit being equal to ‘0’ with respect to each of the upperbit and lower bit, which configures a symbol. Alternatively, the firstsoft decision value may also output (in symbol units) a LLR for thelikelihood of 2 bits being equal to “00”, “01”, “10”, and “11” withrespect to all possible combinations. The first soft decision value isfed-back to the trellis decoding unit 4012 through the inner symbolmapper 4019, the symbol interleaver 4020, and the feedback formatter4021. On the other hand, the second soft decision value indicates adegree of reliability the input bit of the convolution encoder 513included in the transmitting system. Herein, the second soft decisionvalue is represented as the LLR between the likelihood of 1 bit beingequal to ‘1’ and the likelihood of bit being equal to ‘0’. Thereafter,the second soft decision value is outputted to the outer buffer 4022. Inthis case, a maximum a posteriori probability (MAP) or a soft-outViterbi algorithm (SOYA) may be used as the decoding algorithm of thesymbol decoder 4018.

The first soft decision value that is outputted from the symbol decoder4018 is inputted to the inner symbol mapper 4019. The inner symbolmapper 4019 converts the first soft decision value to a data formatcorresponding the input data of the trellis decoding unit 4012.Thereafter, the inner symbol mapper 4019 outputs the converted softdecision value to the symbol interleaver 4020. The operations of theinner symbol mapper 4019 may also vary depending upon the structure andcoding rate of the convolution encoder 513 included in the transmittingsystem.

The symbol interleaver 4020 performs symbol interleaving, as shown inFIG. 30, on the first soft decision value that is outputted from theinner symbol mapper 4019. Then, the symbol interleaver 4020 outputs thesymbol-interleaved first soft decision value to the feedback formatter4021. Herein, the output of the symbol interleaver 4020 also correspondsto a soft decision value.

With respect to the changed processing order of the soft decision valuescorresponding to the symbols that are generated during an intermediatestep, wherein the output symbols outputted from the block processor 302of the transmitting system are being inputted to the trellis encodingmodule (e.g., when the symbols pass through the group formatter, thedata deinterleaver, the packet formatter, the RS encoder, and the datainterleaver), the feedback formatter 4021 alters (or changes) the orderof the output values outputted from the symbol interleaver 4020.Subsequently, the feedback formatter 4020 outputs values to the trellisdecoding unit 4012 in the changed order. The reordering process of thefeedback formatter 4021 may configure at least one of software,hardware, and middleware.

The soft decision values outputted from the symbol interleaver 4020 arematched with the positions of mobile service data symbols each havingthe size of TDL, which are outputted from the input buffer 4011, so asto be in a one-to-one correspondence. Thereafter, the soft decisionvalues matched with the respective symbol position are inputted to thetrellis decoding unit 4012. At this point, since the main service datasymbols or the RS parity data symbols and known data symbols of the mainservice data do not correspond to the mobile service data symbols, thefeedback formatter 4021 inserts null data in the correspondingpositions, thereby outputting the processed data to the trellis decodingunit 4012. Additionally, each time the symbols having the size of TDLare turbo decoded, no value is fed-back by the symbol interleaver 4020starting from the beginning of the first decoding process. Therefore,the feedback formatter 4021 is controlled by the feedback controller4010, thereby inserting null data into all symbol positions including amobile service data symbol. Then, the processed data are outputted tothe trellis decoding unit 4012.

The output buffer 4022 receives the second soft decision value from thesymbol decoder 4018 based upon the control of the feedback controller4010. Then, the output buffer 4022 temporarily stores the receivedsecond soft decision value. Thereafter, the output buffer 4022 outputsthe second soft decision value to the RS frame decoder 2006. Forexample, the output buffer 4022 overwrites the second soft decisionvalue of the symbol decoder 4018 until the turbo decoding process isperformed for M number of times. Then, once all M number of turbodecoding processes is performed for a single TDL, the correspondingsecond soft decision value is outputted to the RS frame decoder 2006.

The feedback controller 4010 controls the number of turbo decoding andturbo decoding repetition processes of the overall block decoder, shownin FIG. 55. More specifically, once the turbo decoding process has beenrepeated for a predetermined number of times, the second soft decisionvalue of the symbol decoder 4018 is outputted to the RS frame decoder2006 through the output buffer 4022. Thus, the block decoding process ofa turbo block is completed. In the description of the present invention,this process is referred to as a regressive turbo decoding process forsimplicity.

At this point, the number of regressive turbo decoding rounds betweenthe trellis decoding unit 4012 and the symbol decoder 4018 may bedefined while taking into account hardware complexity and errorcorrection performance. Accordingly, if the number of rounds increases,the error correction performance may be enhanced. However, this may leadto a disadvantageous of the hardware becoming more complicated (orcomplex).

Meanwhile, the main service data processor 2008 corresponds to blockrequired for receiving the main service data. Therefore, theabove-mentioned blocks may not be necessary (or required) in thestructure of a digital broadcast receiving system for receiving mobileservice data only.

The data deinterleaver of the main service data processor 2008 performsan inverse process of the data interleaver included in the transmittingsystem. In other words, the data deinterleaver deinterleaves the mainservice data outputted from the block decoder 2005 and outputs thedeinterleaved main service data to the RS decoder. The data beinginputted to the data deinterleaver include main service data, as well asmobile service data, known data, RS parity data, and an MPEG header. Atthis point, among the inputted data, only the main service data and theRS parity data added to the main service data packet may be outputted tothe RS decoder. Also, all data outputted after the data derandomizer mayall be removed with the exception for the main service data. In theembodiment of the present invention, only the main service data and theRS parity data added to the main service data packet are inputted to theRS decoder.

The RS decoder performs a systematic RS decoding process on thedeinterleaved data and outputs the processed data to the dataderandomizer.

The data derandomizer receives the output of the RS decoder andgenerates a pseudo random data byte identical to that of the randomizerincluded in the digital broadcast transmitting system. Thereafter, thedata derandomizer performs a bitwise exclusive OR (XOR) operation on thegenerated pseudo random data byte, thereby inserting the MPEGsynchronization bytes to the beginning of each packet so as to outputthe data in 188-byte main service data packet units.

RS Frame Decoder

The data outputted from the block decoder 2005 are in portion units.More specifically, in the transmitting system, the primary RS frame isdivided into several portions, and the mobile service data of eachportion are assigned either to regions A/B/C/D within the general datagroup or only to regions A/B, thereby being transmitted to the receivingsystem. Also, the secondary RS frame is also divided into severalportions, and the mobile service data of each portion are assigned toregions C/D, or the mobile service data are assigned to the bondingregion of the bonding data group, thereby being transmitted to thereceiving system.

Therefore, the RS frame decoder 2006 groups several portions included ina parade so as to form a primary RS frame, or to form a primary RS frameand a second RS frame. Thereafter, error correction decoding isperformed in RS frame units.

For example, when the RS frame mode value is equal to 00, then, oneparade transmits one RS frame. At this point, one RS frame is dividedinto several portions, and the mobile service data of each portion areassigned to regions A/B/C/D of the corresponding general data group,thereby being transmitted. In this case, the RS frame decoder 2006extracts mobile service data from regions A/B/C/D of the correspondinggeneral data group, as shown in FIG. 56( a). Subsequently, the RS framedecoder 2006 may perform the process of forming (or creating) a portionon a plurality of general data group within a parade, thereby formingseveral portions. Then, the several portions of mobile service data maybe grouped to form an RS frame. Herein, if stuffing bytes are added tothe last portion, the RS frame may be formed after removing the stuffingbytes.

In another example, when the RS frame mode value is equal to 01, thenone parade transmits two RS frames, i.e., a primary RS frame and asecondary RS frame. At this point, a primary RS frame is divided intoseveral primary portions, and the mobile service data of each primaryportion are assigned to regions A/B of the corresponding general datagroup, thereby being transmitted. Also, a secondary RS frame is dividedinto several secondary portions, and the mobile service data of eachsecondary portion are assigned to regions C/D of the correspondinggeneral data group, thereby being transmitted. In this case, the RSframe decoder 2006 extracts mobile service data from regions A/B of thecorresponding general data group, as shown in FIG. 56( b. Subsequently,the RS frame decoder 2006 may perform the process of forming (orcreating) a primary portion on a plurality of general data groups withina parade, thereby forming several primary portions. Then, the severalprimary portions of mobile service data may be grouped to form a primaryRS frame. Herein, if stuffing bytes are added to the last primaryportion, the primary RS frame may be formed after removing the stuffingbytes. Also, the RS frame decoder 2006 extracts mobile service data fromregions C/D of the corresponding general data group. Subsequently, theRS frame decoder 2006 may perform the process of forming (or creating) asecondary portion on a plurality of general data groups within a parade,thereby forming several secondary portions. Then, the several secondaryportions of mobile service data may be grouped to form a secondary RSframe. Herein, if stuffing bytes are added to the last secondaryportion, the secondary RS frame may be formed after removing thestuffing bytes.

In yet another example, when the RS frame mode value is equal to 01, themobile service data of each primary portion divided from the primary RSframe is allocated and transmitted to regions A/B within thecorresponding bonding data group. Also, the mobile service data of eachprimary portion divided from the secondary RS frame is allocated andtransmitted to a bonding region within the bonding data group. In thiscase, the RS frame decoder 2006 performs a process of extracting mobileservice data from regions A/B within the bonding data group, so as toconfigure a primary portion, on regions A/B of the multiple bonding datagroups belonging to a single parade. Thus, a plurality of primaryportions may be acquired. Additionally, a plurality of primary portionsmay be grouped to create a primary RS frame. Herein, if stuffing bytesare added to the last primary portion, the primary RS frame may beformed after removing the stuffing bytes. Moreover, the RS frame decoder2006 performs a process of extracting mobile service data from thebonding region within the corresponding bonding data group, so as toconfigure a secondary portion, on the bonding region of the multiplebonding data groups belonging to a single parade. Thus, a plurality ofsecondary portions may be acquired. Additionally, a plurality ofsecondary portions may be grouped to create a secondary RS frame.Herein, if stuffing bytes are added to the last secondary portion, thesecondary RS frame may be formed after removing the stuffing bytes.

More specifically, the RS frame decoder 2006 receives the RS-encodedand/or CRC-encoded mobile service data of each portion from the blockdecoder 2005. Then, the RS frame decoder 2006 groups several portions,which are inputted based upon RS frame-associated information outputtedfrom the operation controller 2000 (or signaling decoder 2013), therebyperforming error correction. By referring to the RS frame mode valueincluded in the RS frame-associated information, the RS frame decoder2006 may form an RS frame and may also be informed of the number of RScode parity data bytes and the code size.

The RS frame decoder 2006 also refers to the RS frame-associatedinformation in order to perform an inverse process of the RS frameencoder, which is included in the transmitting system, therebycorrecting the errors within the RS frame. Thereafter, the RS framedecoder 2006 performs derandomizing on the error-corrected RS framepayload.

Hereinafter, the process of grouping data being transmitted throughgeneral data groups so as to configure an RS frame, and of performingerror correction in RS frame units according to an embodiment of thepresent invention will now be described in detail. In the followingdescription, since the processed described below is similarly applied tothe bonding data group, a detailed description of the bonding data groupwill be omitted for simplicity.

FIG. 57 illustrates, when the RS frame mode value is equal to ‘00’, anexemplary process of grouping several portion being transmitted to aparade, thereby forming an RS frame and an RS frame reliability map.

More specifically, the RS frame decoder 2006 receives and groups aplurality of mobile service data bytes, so as to form an RS frame.According to the present invention, in transmitting system, the mobileservice data correspond to data RS-encoded in RS frame units. At thispoint, the mobile service data may already be error correction encoded(e.g., CRC-encoded). Alternatively, the error correction encodingprocess may be omitted.

It is assumed that, in the transmitting system, an RS frame having thesize of (N+2)×(187+P) bytes is divided into M number of portions, andthat the M number of mobile service data portions are assigned andtransmitted to regions A/B/C/D in M number of general data groups,respectively. In this case, in the receiving system, each mobile servicedata portion is grouped, as shown in FIG. 57( a), thereby forming an RSframe having the size of (N+2)×(187+P) bytes. At this point, whenstuffing bytes (S) are added to at least one portion included in thecorresponding RS frame and then transmitted, the stuffing bytes areremoved, thereby configuring an RS frame and an RS frame reliabilitymap. For example, as shown in FIG. 27, when S number of stuffing bytesare added to the corresponding portion, the S number of stuffing bytesare removed, thereby configuring the RS frame and the RS framereliability map.

Herein, when it is assumed that the block decoder 2005 outputs a softdecision value for the decoding result, the RS frame decoder 2006 maydecide the ‘0’ and ‘1’ of the corresponding bit by using the codes ofthe soft decision value. 8 bits that are each decided as described aboveare grouped to create 1 data byte. If the above-described process isperformed on all soft decision values of several portions (or datagroups) included in a parade, the RS frame having the size of(N+2)×(187+P) bytes may be configured.

Additionally, the present invention uses the soft decision value notonly to configure the RS frame but also to configure a reliability map.

Herein, the reliability map indicates the reliability of thecorresponding data byte, which is configured by grouping 8 bits, the 8bits being decided by the codes of the soft decision value.

For example, when the absolute value of the soft decision value exceedsa pre-determined threshold value, the value of the corresponding bit,which is decided by the code of the corresponding soft decision value,is determined to be reliable. Conversely, when the absolute value of thesoft decision value does not exceed the pre-determined threshold value,the value of the corresponding bit is determined to be unreliable.Thereafter, if even a single bit among the 8 bits, which are decided bythe codes of the soft decision value and group to configure one databyte, is determined to be unreliable, the corresponding data byte ismarked on the reliability map as an unreliable data byte.

Herein, determining the reliability of one data byte is only exemplary.More specifically, when a plurality of data bytes (e.g., at least 4 databytes) are determined to be unreliable, the corresponding data bytes mayalso be marked as unreliable data bytes within the reliability map.Conversely, when all of the data bits within the one data byte aredetermined to be reliable (i.e., when the absolute value of the softdecision values of all 8 bits included in the one data byte exceed thepredetermined threshold value), the corresponding data byte is marked tobe a reliable data byte on the reliability map. Similarly, when aplurality of data bytes (e.g., at least 4 data bytes) are determined tobe reliable, the corresponding data bytes may also be marked as reliabledata bytes within the reliability map. The numbers proposed in theabove-described example are merely exemplary and, therefore, do notlimit the scope or spirit of the present invention.

The process of configuring the RS frame and the process of configuringthe reliability map both using the soft decision value may be performedat the same time. Herein, the reliability information within thereliability map is in a one-to-one correspondence with each byte withinthe RS frame. For example, if a RS frame has the size of (N+2)×(187+P)bytes, the reliability map is also configured to have the size of(N+2)×(187+P) bytes. FIG. 57( a′) and FIG. 57( b′) respectivelyillustrate the process steps of configuring the reliability mapaccording to the present invention.

Subsequently, the RS frame reliability map is used on the RS frames soas to perform error correction.

FIG. 58 illustrates example of the error correction processed accordingto embodiments of the present invention. FIG. 58 illustrates an exampleof performing an error correction process when the transmitting systemhas performed both RS encoding and CRC encoding processes on the RSframe.

As shown in FIG. 58( a) and FIG. 58( a′), when the RS frame having thesize of (N+2)×(187+P) bytes and the RS frame reliability map having thesize of (N+2)×(187+P) bytes are created, a CRC syndrome checking processis performed on the created RS frame, thereby verifying whether anyerror has occurred in each row. Subsequently, as shown in FIG. 58( b), a2-byte checksum is removed to configure an RS frame having the size ofN×(187+P) bytes. Herein, the presence (or existence) of an error isindicated on an error flag corresponding to each row. Similarly, sincethe portion of the reliability map corresponding to the CRC checksum hashardly any applicability, this portion is removed so that only N×(187+P)number of the reliability information bytes remain, as shown in FIG. 58(b′).

After performing the CRC syndrome checking process, as described above,a RS decoding process is performed in a column direction. Herein, a RSerasure correction process may be performed in accordance with thenumber of CRC error flags. More specifically, as shown in FIG. 58( c),the CRC error flag corresponding to each row within the RS frame isverified. Thereafter, the RS frame decoder 2006 determines whether thenumber of rows having a CRC error occurring therein is equal to orsmaller than the maximum number of errors on which the RS erasurecorrection may be performed, when performing the RS decoding process ina column direction. The maximum number of errors corresponds to P numberof parity bytes inserted when performing the RS encoding process. In theembodiment of the present invention, it is assumed that 48 parity byteshave been added to each column (i.e., P=48).

If the number of rows having the CRC errors occurring therein is smallerthan or equal to the maximum number of errors (i.e., 48 errors accordingto this embodiment) that can be corrected by the RS erasure decodingprocess, a (235,187)-RS erasure decoding process is performed in acolumn direction on the RS frame having (187+P) number of N-byte rows(i.e., 235 N-byte rows), as shown in FIG. 58( d). Thereafter, as shownin FIG. 58( e), the 48-byte parity data that have been added at the endof each column are removed. Conversely, however, if the number of rowshaving the CRC errors occurring therein is greater than the maximumnumber of errors (i.e., 48 errors) that can be corrected by the RSerasure decoding process, the RS erasure decoding process cannot beperformed. In this case, the error may be corrected by performing ageneral RS decoding process. In addition, the reliability map, which hasbeen created based upon the soft decision value along with the RS frame,may be used to further enhance the error correction ability (orperformance) of the present invention.

More specifically, the RS frame decoder 2006 compares the absolute valueof the soft decision value of the block decoder 2005 with thepre-determined threshold value, so as to determine the reliability ofthe bit value decided by the code of the corresponding soft decisionvalue. Also, 8 bits, each being determined by the code of the softdecision value, are grouped to form one data byte. Accordingly, thereliability information on this one data byte is indicated on thereliability map. Therefore, as shown in FIG. 58( c), even though aparticular row is determined to have an error occurring therein basedupon a CRC syndrome checking process on the particular row, the presentinvention does not assume that all bytes included in the row have errorsoccurring therein. The present invention refers to the reliabilityinformation of the reliability map and sets only the bytes that havebeen determined to be unreliable as erroneous bytes. In other words,with disregard to whether or not a CRC error exists within thecorresponding row, only the bytes that are determined to be unreliablebased upon the reliability map are set as erasure points.

According to another method, when it is determined that CRC errors areincluded in the corresponding row, based upon the result of the CRCsyndrome checking result, only the bytes that are determined by thereliability map to be unreliable are set as errors. More specifically,only the bytes corresponding to the row that is determined to haveerrors included therein and being determined to be unreliable based uponthe reliability information, are set as the erasure points. Thereafter,if the number of error points for each column is smaller than or equalto the maximum number of errors (i.e., 48 errors) that can be correctedby the RS erasure decoding process, an RS erasure decoding process isperformed on the corresponding column. Conversely, if the number oferror points for each column is greater than the maximum number oferrors (i.e., 48 errors) that can be corrected by the RS erasuredecoding process, a general decoding process is performed on thecorresponding column.

More specifically, if the number of rows having CRC errors includedtherein is greater than the maximum number of errors (i.e., 48 errors)that can be corrected by the RS erasure decoding process, either an RSerasure decoding process or a general RS decoding process is performedon a column that is decided based upon the reliability information ofthe reliability map, in accordance with the number of erasure pointswithin the corresponding column. For example, it is assumed that thenumber of rows having CRC errors included therein within the RS frame isgreater than 48. And, it is also assumed that the number of erasurepoints decided based upon the reliability information of the reliabilitymap is indicated as 40 erasure points in the first column and as 50erasure points in the second column. In this case, a (235,187)-RSerasure decoding process is performed on the first column.Alternatively, a (235,187)-RS decoding process is performed on thesecond column. When error correction decoding is performed on all columndirections within the RS frame by using the above-described process, the48-byte parity data which were added at the end of each column areremoved, as shown in FIG. 58( e).

As described above, even though the total number of CRC errorscorresponding to each row within the RS frame is greater than themaximum number of errors that can be corrected by the RS erasuredecoding process, when the number of bytes determined to have a lowreliability level, based upon the reliability information on thereliability map within a particular column, while performing errorcorrection decoding on the particular column. Herein, the differencebetween the general RS decoding process and the RS erasure decodingprocess is the number of errors that can be corrected. Morespecifically, when performing the general RS decoding process, thenumber of errors corresponding to half of the number of parity bytes(i.e., (number of parity bytes)/2) that are inserted during the RSencoding process may be error corrected (e.g., 24 errors may becorrected). Alternatively, when performing the RS erasure decodingprocess, the number of errors corresponding to the number of paritybytes that are inserted during the RS encoding process may be errorcorrected (e.g., 48 errors may be corrected).

After performing the error correction decoding process, as describedabove, a RS frame payload configured of 187 N-byte rows (or packet) maybe obtained as shown in FIG. 58( e). At this point, the RS frame payloadhaving the size of N×187 bytes is performed a derandomizing process,which corresponds to the inverse process of the randomizer included inthe transmitting system and then the derandomized data are outputted,thereby obtaining the mobile service data transmitted from thetransmitting system. In the present invention, the RS frame decoder 2006may perform the data derandomizing function.

An RS frame decoder may be configured of M number of RS frame decodersprovided in parallel, wherein the number of RS frame encoders is equalto the number of parades (=M) within an M/H frame, a multiplexer formultiplexing each portion and being provided to each input end of the Mnumber of RS frame decoders, and a demultiplexer for demultiplexing eachportion and being provided to each output end of the M number of RSframe decoders.

As described above, the transmitting system, the receiving system, andthe method of processing broadcast signal are advantageous in that, whentransmitting mobile service data through a channel, the presentinvention is robust against any error and is also backward compatiblewith the conventional receiver.

Moreover, the present invention may also receive the mobile service datawithout any error occurring, even in channels having severe ghost effectand noise.

By inserting known data in a specific position of the data region and bytransmitting the processed data packets, the present invention mayenhance the receiving performance of the receiving system in anenvironment undergoing frequent channel changes.

Also, by using at least a portion of a channel capacity, through whichdata for the conventional main service have been transmitted, thetransmission rate of the mobile serice data.

Furthermore, the present invention is even more effective when appliedto mobile and portable receivers, which are also liable to a frequentchange in channel and which require protection (or resistance) againstintense noise.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A receiving system, comprising: a tuner configured to receive abroadcast signal including first mobile service data and second mobileservice data through a slot, wherein the slot is configured of M1 numberof packets, wherein, among the M1 number of packets included in theslot, M2 number of packets include the first mobile service data and aplurality of known data sequences, wherein, among remaining M3 number ofpackets, at least one packet includes the second mobile service data andwherein M1=M2+M3, M2>M3; a demodulator configured to demodulate thebroadcast signal; a block decoder configured to perform turbo-decodingon the first and second mobile service data included in the demodulatedbroadcast signal; and a Reed-Solomon (RS) frame decoder configured tobuild a primary RS frame by collecting the turbo-decoded first mobileservice data, to perform error correction decoding on the primary RSframe, to build a secondary RS frame by collecting the second mobileservice data and to perform error correction decoding on the secondaryRS frame.
 2. The receiving system of claim 1, wherein, among the M2number packets included in the slot, at least one packet includes bothfirst mobile service data and second mobile service data.
 3. Thereceiving system of claim 1, wherein, among the M3 number packetsincluded in the slot, at least one packet includes a long known datasequence.
 4. The receiving system of claim 1, wherein, among the M3number packets included in the slot, at least one packet includes secondmobile service data and a plurality of short known data sequences. 5.The receiving system of claim 3, further comprising: a channel equalizerconfigured to perform channel equalization on the first mobile servicedata included in the demodulated broadcast signal based on an indirectequalization method that estimates channel impulse responses (CIRs)using the known data sequences and calculates an equalizationcoefficient by interpolating or extrapolating the estimated CIRs, andperform channel equalization on the second mobile service data includedin the demodulated broadcast signal based on a direct equalizationmethod that extracts an error from a output of the channel equalizer andupdates an equalization coefficient based on the extracted error.
 6. Thereceiving system of claim 3, further comprising: a channel equalizerconfigured to perform channel equalization on the first and secondmobile service data included in the demodulated broadcast signal basedon an indirect equalization method that estimates CIRs using the knowndata sequences and calculates an equalization coefficient byinterpolating or extrapolating the estimated CIRs.
 7. The receivingsystem of claim 1, wherein, among the M3 number packets included in theslot, at least one packet includes main service data.
 8. The receivingsystem of claim 1, wherein M1 is equal to 156, wherein M2 is equal to118, and wherein M3 is equal to
 38. 9. A method for processing broadcastsignals in a receiving system, comprising: receiving a broadcast signalincluding first mobile service data and second mobile service datathrough a slot, wherein the slot is configured of M1 number of packets,wherein, among the M1 number of packets included in the slot, M2 numberof packets include the first mobile service data and a plurality ofknown data sequences, wherein, among remaining M3 number of packets, atleast one packet includes the second mobile service data and whereinM1=M2+M3, M2>M3; demodulating the broadcast signal; performingturbo-decoding on the first and second mobile service data included inthe demodulated broadcast signal; building a primary RS frame bycollecting the turbo-decoded first mobile service data and performingerror correction decoding on the primary RS frame; and building asecondary RS frame by collecting the second mobile service data andperforming error correction decoding on the secondary RS frame.
 10. Themethod of claim 9, wherein, among the M2 number packets included in theslot, at least one packet includes both first mobile service data andsecond mobile service data.
 11. The method of claim 9, wherein, amongthe M3 number packets included in the slot, at least one packet includesa long known data sequence.
 12. The method of claim 9, wherein, amongthe M3 number packets included in the slot, at least one packet includessecond mobile service data and a plurality of short known datasequences.
 13. The method of claim 11, further comprising: performingchannel equalization on the first mobile service data included in thedemodulated broadcast signal based on an indirect equalization methodthat estimates channel impulse responses (CIRs) using the known datasequences and calculates an equalization coefficient by interpolating orextrapolating the estimated CIRs; and performing channel equalization onthe second mobile service data included in the demodulated broadcastsignal based on a direct equalization method that extracts an error froma output of the channel equalizer and updates an equalizationcoefficient based on the extracted error.
 14. The method of claim 11,further comprising: performing channel equalization on the first andsecond mobile service data included in the demodulated broadcast signalbased on an indirect equalization method that estimates CIRs using theknown data sequences and calculates an equalization coefficient byinterpolating or extrapolating the estimated CIRs.
 15. The method ofclaim 9, wherein, among the M3 number packets included in the slot, atleast one packet includes main service data.
 16. The receiving system ofclaim 4, further comprising: a channel equalizer configured to performchannel equalization on the first mobile service data included in thedemodulated broadcast signal based on an indirect equalization methodthat estimates channel impulse responses (CIRs) using the known datasequences and calculates an equalization coefficient by interpolating orextrapolating the estimated CIRs, and perform channel equalization onthe second mobile service data included in the demodulated broadcastsignal based on a direct equalization method that extracts an error froma output of the channel equalizer and updates an equalizationcoefficient based on the extracted error.
 17. The receiving system ofclaim 4, further comprising: a channel equalizer configured to performchannel equalization on the first and second mobile service dataincluded in the demodulated broadcast signal based on an indirectequalization method that estimates CIRs using the known data sequencesand calculates an equalization coefficient by interpolating orextrapolating the estimated CIRs.
 18. The method of claim 12, furthercomprising: performing channel equalization on the first mobile servicedata included in the demodulated broadcast signal based on an indirectequalization method that estimates channel impulse responses (CIRs)using the known data sequences and calculates an equalizationcoefficient by interpolating or extrapolating the estimated CIRs; andperforming channel equalization on the second mobile service dataincluded in the demodulated broadcast signal based on a directequalization method that extracts an error from a output of the channelequalizer and updates an equalization coefficient based on the extractederror.
 19. The method of claim 12, further comprising: performingchannel equalization on the first and second mobile service dataincluded in the demodulated broadcast signal based on an indirectequalization method that estimates CIRs using the known data sequencesand calculates an equalization coefficient by interpolating orextrapolating the estimated CIRs.